FR2854401A1 - Optically active polymers prepared by polymerizing chiral 2,2'-bis(diarylphosphino)-1,1'-binaphthyl derivatives with other monomers, e.g. useful for preparing asymmetric hydrogenation catalysts - Google Patents

Abstract

Optically active polymers (I) prepared by polymerizing chiral 2,2'-bis(diarylphosphino)-1,1'-binaphthyl derivatives (II) with other monomers are new. Optically active polymers (I) prepared by polymerizing chiral 2,2'-bis(diarylphosphino)-1,1'-binaphthyl derivatives of formula (II) with other monomers are new. [Image] R1, R2H or substituents; Ar1, Ar2alkyl, alkenyl, cycloalkyl, aryl or aralkyl; X1NH2, CH2NH2, OH, CH2OH, COOH, ester, NCO or CH2NCO. Independent claims are also included for: (1) production of (I) by polymerizing (II) with other monomers; (2) transition metal complexes of (I); (3) racemic polymers (Ia) corresponding to (I).

Description

CHIRAL DIPHOSPHINES IN INSOLUBLE FORM,

THEIR PREPARATION AND THEIR USES AS LIGANDS IN

THE SYNTHESIS OF COMPLEXES FOR CATALYSIS

ASYMMETRIC.
The present invention relates to the preparation of chiral diphosphines in insoluble form. More exactly, the invention resides in an optically active polymer wherein one of the polymeric units is a chiral diphosphine.
The invention also relates to the use of said polymer as a ligand in the preparation of metal complexes for asymmetric catalysis.
The production of pure optically active compounds is a problem that arises in many technical fields such as, for example, pharmacy, agrochemicals, the food industry (food additives, flavorings) and also in the perfume industry.
This problem is expected to become increasingly important as more and more we find that in a given application only one of the stereomers has the desired property.
In recent years, asymmetric catalysis has grown considerably. It has the advantage of leading directly to the preparation of optically pure isomers by asymmetric induction without the need to duplicate racemic mixtures.
2,2'-bis (diphenylphosphino) -1,1'-binaphthyl (BINAP) is an example of a disphospore ligand commonly used for the preparation of metal complexes for the asymmetric catalysis of hydrogenation, carbonylation and hydrosilylation reactions. , CC bond formation (such as allylic substitutions or Grignard cross-couplings) or even asymmetric isomerization of allylamines.
The complexes used are derived from palladium, ruthenium, rhodium and iridium salts and are therefore derived from particularly expensive metals.
There is a need for the possibility of recycling chiral catalysts which are generally expensive, while maintaining or improving their effectiveness.
We are therefore witnessing the development of heterogeneous catalysis, in particular solid-liquid or liquid-liquid catalysis.
Thus, it has been proposed according to WO 00/52081, an optically active polymer obtained by polymerization of a chiral diphosphine having two identical functional groups capable of reacting with polymerizable monomers.
An example of a particularly preferred polymer is a polymer having as recurrent pattern:

wherein - G1 and G2 independently represent a saturated or aromatic carbocyclic group; and - J represents a divalent hydrocarbon group of aliphatic, alicyclic and / or aromatic nature; the degree of polymerization is preferably between 2 and 100, more preferably between 2 and 50.
The polymer therefore involves a chiral body, a diphosphine comprising naphthyl groups which have two aminomethyl groups located in the 6 and 6 'position.
But the preparation of this phosphine has many steps that are not easily achievable industrially:

Continuing its research, the Applicant has found that it is possible to prepare an optically active polymer from diphosphine precursors that can be prepared much more easily on an industrial scale because they derive from a commercial product namely 2, 2'-bis (diphenylphosphino) -1,1'binaphthyl (BINAP) or BINAP and their preparation does not involve difficult steps to implement.
It has been found that the use of a diphosphinic monomer having 4,4'-substituents on naphthyl groups does not affect the ability of the obtained polymer to act as a chiral ligand in asymmetric catalysts.
A first object of the invention is an optically active polymer thus making it possible to insolubilize a chiral diphosphine.
Other objects of the invention are the processes for preparing said polymer, the metal complexes involving it as a ligand and their uses in asymmetric catalysis.
The present invention thus provides a diphosphine which can be used as a ligand and insolubilized in the form of an optically active polymer obtainable by polymerization of a chiral diphosphine with one or more polymerizable monomers characterized in that said chiral diphosphine constituted of a chiral body carrying two identical functional groups capable of reacting with said polymerizable monomers, corresponds to the following formula:

in said formula: - R1, R2, which may be identical or different, represent a hydrogen atom or a substituent, - Ar1 and Ar2 independently represent an alkyl, alkenyl, cycloalkyl, aryl or arylalkyl group, - X1 represents a functional group chosen from the groups : amino, aminomethyl, hydroxy, hydroxymethyl, carboxylic, ester, isocyanato, isocyanatomethyl.
Another object of the invention is constituted by the use of the optically active polymer as a ligand in the preparation of metal complexes intended for asymmetric catalysis. Within the context of the invention, the term alkyl is understood to mean a linear or branched hydrocarbon chain. having 1 to 15 carbon atoms and preferably 1 or 2 to 10 carbon atoms.
Examples of preferred alkyl groups include methyl, ethyl, propyl, isopropyl, butyl, isobutyl and t-butyl.
By alkenyl is meant a linear or branched hydrocarbon group having from 2 to 15 carbon atoms, comprising one or more double bonds, preferably 1 to 2 double bonds.
Cycloalkyl means a monocyclic cyclic hydrocarbon group comprising from 3 to 8 carbon atoms, preferably a cyclopentyl or cyclohexyl or polycyclic (bicyclic or tricyclic) group comprising from 4 to 18 carbon atoms, especially adamantyl or norbornyl.
By aryl is meant an aromatic mono- or polycyclic group, preferably mono- or bicyclic comprising from 6 to 20 carbon atoms, preferably phenyl or naphthyl. When the group is polycyclic, that is to say that it comprises more than one ring nucleus, the ring nuclei can be condensed two by two or attached two by two by a bonds.
Examples of (C 6 -C 18) aryl groups include phenyl, naphthyl, anthryl and phenanthryl.
By arylalkyl is meant a linear or branched hydrocarbon group bearing a monocyclic aromatic ring and comprising from 7 to 12 carbon atoms, preferably benzyl.
In the formula (II), the carbocyclic groups Ar1 and Ar2 may carry substituents which are such that they do not interfere with the complexation of the ligand to the metal during the preparation of the catalyst.
Examples of substituents are alkyl, alkoxy, thioalkoxy, alkoxyalkyl, thioalkoxyalkyl, polyoxyalkylene, -SO3H, -SO3M where M is a metal or ammonium cation, -PO3H2, -PO3HM or -PO3M2 where M is as defined above. .
Preferably, M is an alkali metal cation such as Na, Li or K.
It is desirable that the substituents do not interfere with the reactions used in the preparation of the compounds (II) from the precursors from which they are derived. However, steps of protection and deprotection can be considered, if necessary. The skilled person can refer to the following Protective Groups in Organic Synthesis, Greene TW and Wuts PGM, ed. John Wiley and Sons, 1991 to achieve the protection of particular organic functions:
In the alkyl, alkoxy, thioalkoxy, alkoxyalkyl and thioalkoxyalkyl groups, the alkyl parts are saturated, linear or branched hydrocarbon groups, in particular comprising up to 25 carbon atoms, and, for example, from 1 to 12 carbon atoms, more preferably from 1 to 6 carbon atoms.
Examples of alkyl groups are methyl, ethyl, propyl, isopropyl, butyl, isobutyl, t-butyl, pentyl, isopentyl, neopentyl, 2-methylbutyl, 1-ethylpropyl, hexyl, isohexyl, neohexyl, 1-methylpentyl, 3-methylpentyl, 1, 1-dimethylbutyl, 1,3-dimethylbutyl, 2-ethylbutyl, 1-methyl-1-ethylpropyl, heptyl, 1-methylhexyl, 1-propylbutyl, 4,4-dimethylpentyl, octyl, 1-methylheptyl, 2-ethylhexyl, 5,5- dimethylhexyl, nonyl, decyl, 1-methylnonyl, 3,7-dimethyloctyl and 7,7-dimethyloctyl.
Preferably, the substituents are alkyl or alkoxy groups preferably having from 1 to 6 carbon atoms.
According to the present invention, the preferred ligands respectively correspond to formulas (II) in which Ar1, Ar2 independently represent a (C1-C6) alkyl group; a phenyl group optionally substituted with one or more (C1-C6) alkyl or (C1-C6) alkoxy; or a (C4Cs) cycloalkyl group optionally substituted with one or more (C1-C6) alkyl groups.
Among the preferred compounds of formula (II) are those for which Ar1 and Ar2 are independently (C1-C4) alkyl; a phenyl group optionally substituted by methyl or tert-butyl; or a (C5C6) cycloalkyl group optionally substituted by methyl or tert-butyl.
The compounds of formula (II) in which Ar1 and Ar2 are identical and preferably represent a phenyl group are most particularly preferred.
The naphthyl groups may also carry a substituent represented by R 1 or R 2 which may be of any nature insofar as they do not interfere with the preparation and reactivity of the catalysts.
In formula (1), R 1, R 2 preferably represent a hydrogen atom, one or more groups selected from (C 1 -C 6) alkyl and (C 1 -C 6) alkoxy.
The preferred compounds (II) do not carry a substituent, which means that R 1 and R 2 represent a hydrogen atom.
As regards the definition of Xi, it may be an amino group -NH2, an aminomethyl group -CH2-NH2, a hydroxyl group -OH, a hydroxymethyl group -CH2-OH, a carboxylic or ester group -COORa (Ra represents a hydrogen atom or an alkyl, cycloalkyl, arylalkyl, phenyl group, more preferentially a hydrogen atom or a CiC2 alkyl group), an isocyanato group -N = C = O, an isocyanatomethyl group -CH2- N = C = O.
The polymer of the invention consists of a sequence of two types of patterns.
The first type of unit is the remainder of the chiral diphosphine corresponding to formula (II) and carrying two identical polymerizable functional groups.
The second type of unit is the remainder of a monomer polymerizable with said functional groups, that is to say a monomer comprising at least two identical functional groups capable of reacting with the functional groups of the chiral diphosphine.
The preferred monomer is difunctional and can be represented by the following formula (I):

in which: M represents a divalent aliphatic hydrocarbon group, alicyclic and / or aromatic, X2 represents a functional group, preferably a carboxylic group, ester, hydroxy, amino, isocyanato, aldehyde, ketone.
The size of the group M will be adjusted by those skilled in the art depending on the end use of the ligand and in particular as a function of the reaction that must catalyze the metal complex formed from this polymeric ligand.
Preferred meanings will be given later for the reagents chosen preferentially.
It will be specified that the monomers most often used correspond to formula (I) in which M represents a C1-C12, preferably C1-C6, alkylene chain; a cycloalkylene group, preferably cyclohexylene; an arylene group, preferably phenylene, tolylene or naphthalene.
Thus, the optically active polymer resulting from the polymerization of the chiral diphosphine of formula (II) and the monomer of formula (I) comprises the following recurring unit:

in which - R 1, R 2, which are identical or different, represent a hydrogen atom or a substituent, - Ar 1 and Ar 2 independently represent an alkyl, alkenyl, cycloalkyl, aryl or arylalkyl group; - M represents a divalent hydrocarbon group with aliphatic, alicyclic character; and / or aromatic; Fi represents the functional group resulting from the reaction: of the group X 1 selected from the groups: amino, aminomethyl, hydroxy, hydroxymethyl, carboxylic, ester, isocyanato, isocyanatomethyl, and X2 group selected from carboxylic, ester, hydroxy, amino, isocyanato, aldehyde, ketone, - the degree of polymerization is preferably between 2 and 100, more preferably between 2 and 50.
The choice of these functions, combined with the choice of polymerizable monomers, determines the nature of the resulting polymer.
Thus, Fi represents more particularly: a urea group (Fi) resulting from the reaction of an amino or aminomethyl group (X 1) with an isocyanato group (X 2) or an isocyanato or isocyanatomethyl group (X 1) with an amino group (X 2 a urethane group (Fi) resulting from the reaction of an isocyanato or isocyanatomethyl group (X1) with a hydroxyl group (X2) or a hydroxyl or hydroxymethyl group (X1) with an isocyanato group (X2), - a group ester (Fi) resulting from the reaction of a carboxylic group or ester (Xi) with a hydroxyl group (X2) or a hydroxyl or hydroxymethyl group (X1) with a carboxylic or ester group (X2), - an amide group (F1 ) resulting from the reaction of a carboxylic group (X1) with an amino group (X2) or an amino or aminomethyl group (X1) with a carboxylic group (X2), - an imine group (Fi) resulting from the reaction of an amino or aminomethyl group (Xi) with an aldehyde or ketone group (X2).
The present invention encompasses all types of polymers and in particular linear polymers, branched or crosslinked. Polymers such as polyester, polyurethane, polyamide, polyurea, polyimine and polyimide may be mentioned.
The preferred polymers are linear polymers but the invention does not exclude crosslinked polymers obtained by using a polymerizable monomer comprising more than two functional groups, for example three groups.
The choice of the monomers put together will depend on their ease of access.
Thus, the invention favors the chiral body bearing, as functional groups, two amino groups and even more preferably two aminomethyl groups corresponding to the following formula:

in said formula: - Ri, R2, Ar1 and Ar2 have the meaning given above.
The compound of formula (IIa) may be prepared by carrying out the following process, which comprises the following steps:
i) carrying out the substitution of the two bromine atoms by cyano groups by reacting the diphosphine in the form of dioxide and dibromea in the 4,4'-position of formula (III):

in said formula: - R1, R2, Ar1 and Ar2 have the meaning given above, by means of a suitable nucleophilic agent so as to obtain the corresponding dicyane (IV),

in said formula: - R1, R2, Ar1 and Ar2 have the meaning given above, ii) carry out the reduction of the diphosphine in the form of dioxide and dicyan in the 4,4'-position of formula (IV), to diphosphine of formula (V ):

in said formula: - R1, R2, Ar1 and Ar2 have the meaning given above.
(iii) reducing the cyano group of the dicyanated diphosphine to a diaminomethyl compound having the formula (IIa).
Diphosphine in the form of dioxide and dibromated at the 4,4'-position of formula (III) is known. It can be obtained by carrying out the bromination of the diphosphine in the form of a dioxide of formula (VI):

in said formula: - R1, R2, Ar1 and Ar2 have the meaning given above.
The diphosphine in the form of the formula (VI) dioxide is known. It can be obtained by oxidation of the diphosphine of formula (VII):

in said formula: - Ri, R2, Ar1 and Ar2 have the meaning given above.
The diphosphine oxide form of formula (VI) is obtained by oxidation using an oxidizing agent of the diphosphine of formula (VII).
Although any type of oxidizing agent, a chemical oxidant, for example potassium permanganate or molecular oxygen or a gas containing it may be used, it is preferred to use hydrogen peroxide, preferably in the form of an aqueous solution.
The concentration of the hydrogen peroxide solution is advantageously between 10% and 35% by weight.
The amount of oxidizing agent used may vary widely from the stoichiometric amount to a 100% excess over stoichiometry.
An organic solvent is used which solubilizes the diphosphine. The solvent may be chosen from aliphatic, cycloaliphatic or aromatic hydrocarbons, chlorinated or otherwise. Examples include dichloromethane, chloroform, carbon tetrachloride, 1,2-dichloroethane.
The concentration of the diphosphine in the reaction solvent is preferably between 0.1 and 50 g / l.
The diphosphine dissolved generally is then contacted in a suitable solvent in contact with the oxidizing agent.
The reaction is conveniently carried out at room temperature, most often between -5 [deg] C and 25 [deg] C.
The reaction time is usually between 30 minutes and 6 hours.
The diphosphine in the form of dioxide is recovered in the organic phase.
The aqueous and organic phases are separated.
A conventional phase treatment is carried out.
Thus, the organic phase is washed with sodium bisulfite which eliminates in the aqueous phase the excess of oxidizing agent (peroxide) which has not reacted.
A usual drying operation is preferably carried out on desiccant, for example sodium or magnesium sulphate.
A diphosphine is obtained in the form of a dioxide having the formula (VI) and designated hereinafter by diphosphine (PO).

In a next step, the bromination is carried out in position 4 and 4 '.
The bromination reaction of the phenyl ring is an electrophilic reaction which is carried out by the action of Br 2 on the diphosphine in the form of dioxide.
A preferred variant of the invention is to add a base, preferably a tertiary amine to trap the hydracid released.
Examples of such amines include triethylamine, tri-n-propylamine, tri-n-butylamine, methyldibutylamine, methyldicyclohexylamine, ethyldiisopropylamine, N, N-diethylcyclohexylamine, dimethylamino-4-pyridine, pyridine, 2,4,6-trimethylpyridine (collidine), N-methylpiperidine, N-ethylpiperidine, Nn-butylpiperidine, 1,2-dimethylpiperidine, N-methylpyrrolidine, 1,2-dimethylpyrrolidine.
Pyridine is preferably chosen.
The amount of tertiary amine used should be sufficient to neutralize the hydracid released by the reaction. Generally, at least the stoichiometric amount is used up to an excess of 20% with respect to stoichiometry.
According to a preferred embodiment of the invention, the bromination takes place in an inert aprotic solvent such as a halogenated aromatic hydrocarbon (for example chlorobenzene and dichlorobenzene); a nitrated aromatic hydrocarbon such as a nitrobenzene; an optionally halogenated aliphatic hydrocarbon such as dichloromethane, carbon tetrachloride or dichloroethane.
As a preferred solvent, mention may be made of halogenated aliphatic hydrocarbons and especially dichloromethane.
Preferably, the molar ratio of the brominating agent to diphosphine (PO) varies between 2 and 5, more preferably between 2 and 3.
When working in solution, the concentration of the reagents can vary very widely between 0.01 and 10 mol / l, for example between 0.05 and 1 mol / l.
The bromination reaction is carried out between 10 ° C. and 60 ° C., preferably between 15 ° C. and 30 ° C. and advantageously, protected from light so that avoid parasitic radical reactions.
A dibrominated diphosphine (PO) corresponding to formula (III) is thus obtained.
It is recovered in a conventional manner: neutralization of excess bromine by sodium bisulfite, treatment with a base (carbonate or sodium hydrogencarbonate), separation of the aqueous and organic phases and recovery of the diphosphine (PO) dibromized at from the organic phase which is dried and removal of the organic solvent.
It should be noted that the invention also includes the variant in which the bromination step is replaced by a chlorination step performed in a similar manner. However, bromination is preferred.
In the next step, the bromine atoms are substituted with cyano groups.
The next step is an aromatic nucleophilic substitution. The two bromine atoms carried by the naphthyl rings are displaced by cyano groups by the action of a suitable nucleophilic agent.
In order to achieve this substitution, those skilled in the art can use any of the methods known in the art.
According to a preferred embodiment of the invention, the nucleophilic agent used is copper cyanide (1).
The molar ratio of copper cyanide to the compound of formula (III) is preferably greater than 2, it may advantageously vary between 2 and 4, preferably between 2 and 3.
The reaction is preferably carried out in a solvent. Examples of solvents include amides such as dimethylformamide, N-methyl-2-pyrrolidinone and hexamethylphosphorylamide. Dimethylformamide is clearly preferred. Pyridine is also a suitable solvent.
The temperature of the reaction is advantageously maintained between 50 [deg] C and 200 [deg] C, preferably between 100 [deg] C and 190 [deg] C.
The concentration of the reactants in the reaction medium generally oscillates between 0.1 and 5 mol / l, for example between 2 and 4 mol / l.
The isolation of the nitrile involves the decomposition of the intermediate complex formed and the trapping of the excess cyanide.
The hydrolysis of the intermediate complex may be carried out either by the action of hydrated iron chloride or by the action of aqueous ethylenediamine.
In the first case, the reaction medium is poured into an aqueous solution of 50-80% iron chloride (g / ml) containing concentrated hydrochloric acid. The resulting solution is heated to 40-80 [deg] C until complete decomposition of the complex. Then the medium is decanted and extracted in a conventional way.
In the second case, the reaction medium is poured into an aqueous solution of ethylenediamine (ethylenediamine / water: 1/5 - 1/1 (v / v), for example 1/3) and then the whole is stirred vigorously. The medium is then decanted and extracted in a manner known per se.
The skilled person can draw inspiration from the work of L. Friedman et al. published in JOC 1961, 26, 1522, to isolate the nitrile.
The reduction of the diphosphine in the form of dioxide is then carried out.
Starting from the dicyanated diphosphine (PO) of formula (IV), the compound of formula (V) is obtained.
This step consists in subjecting the latter to a reduction carried out using a hydrogenosilane.
The latter can be represented by the following formula:

in said formula: - Ra, Rbeta, R, identical or different, represent, a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, a phenyl group or a chlorine atom, - at most two of the groups Ra, Rbeta, R0, represent a hydrogen atom. The preferred reducing agents have the formula (Fa) wherein Ra, Rbeta, R6, represent a hydrogen atom, a methyl group, a phenyl group or a chlorine atom.
As examples of reducing agents, there may be mentioned more particularly: - AIH 3, - PhSiH 3, - HSiCl 3, - (CH 2) 2 HSiCl, - CH 3 HSiCl - PMHS or polymethylhydrosiloxane.
The invention does not exclude any other type of organosilicon compound comprising an SiH group.
The amount of reducing agent is most often in large stoichiometric excess.
Thus, the ratio between the number of moles of reducing agent and the number of moles of diphosphine (PO) varies between 10 and 70.
Among the above-mentioned reducing agents, a mixture of PhSiH 3 (or PMHS) and HSiCl 3 is used.
In this case, the amount of PhSiH3 is such that the ratio between the number of moles of PhSiH3 and moles of diphosphine (PO) varies between 50 and 70.
With regard to the amount of HSiCl3, the ratio of the number of moles of HSiCl3 to the number of moles of diphosphine (PO) varies between 10 and 40.
The reduction reaction is conducted at a temperature advantageously chosen between 80 [deg] C and 130 [deg] C.
At the end of the reaction, the medium is cooled to room temperature and the product is recovered in solid form after evaporation.
One or more washings of the product may be carried out using an organic solvent, preferably an aliphatic hydrocarbon, cycloaliphatic or aromatic, halogenated or not. Preferred solvents include pentane, hexane or cyclohexane.
A diphosphine having the formula (V) is obtained.
An access route to the compounds of formula (IIa) consists in converting the compounds of formula (V) (which have two cyano functions) into corresponding diaminomethyl compounds.
In this case, the reduction of the nitrile function of the compound of formula (V) is carried out by the action of a reducing agent so as to obtain a compound of formula (a):

in said formula: - R1, R2, Ar1 and Ar2 have the meaning given above.
The reduction of the cyano group is thus carried out.
A suitable reducing agent is lithium aluminum hydride (LiAlH 4) but it is also possible to use other reducing agents.
The reaction is preferably carried out in a solvent or a mixture of solvents.
When the reducing agent is LiAlH 4, the solvent advantageously comprises one or more aromatic hydrocarbons (such as benzene, toluene and xylene) in admixture with one or more ethers.
As ethers, mention may be made of C 1 -C 6 alkyl ethers (diethyl ether and diisopropyl ether), cyclic ethers (dioxane, tetrahydrofuran), dimethoxyethane and diethylene glycol dimethyl ether.
Cyclic ethers of the tetrahydrofuran type are preferred.
When the reducing agent is LiAlH 4, it is preferable to opt for a mixture of toluene and tetrahydrofuran in proportions varying between (v / v) 70-50 / 30-50: toluene / tetrahydrofuran (for example 60/40: toluene / THF).
The reduction can be carried out at a temperature of between 20 ° C. and 100 ° C., preferably between 40 ° C. and 80 ° C.
Usually, a large excess of the reducing agent is used. Thus, the molar ratio of the reducing agent to the compound of formula (V) generally varies between 1 and 30, for example between 2 and 20, in particular between 5 and 18.
The concentration of the reagents in the medium is variable; it can be maintained between 0.005 and 1 mol / l.
A compound of formula IIa) is obtained which can be recovered in a conventional manner, in particular by treatment with a base (sodium hydroxide) to remove the aluminates followed by filtration, drying and evaporation.
The compounds used preferably, corresponding to the formula (IIa) in which Ar1 and Ar2 are independently selected from phenyl optionally substituted by methyl or tert-butyl; and (C5-C6) cycloalkyl optionally substituted by methyl or tert-butyl.
Those of formula (IIa) in which Ar1 and Ar2 are identical and represent a phenyl group are more preferably chosen.
A second group of chiral bodies consists of compounds of formula (II) in which X 1 represents an amino group. They can be symbolized by the following formula:

in said formula: - R1, R2, Ar1 and Ar2 have the meaning given above, - Ra represents a hydrogen atom or an alkyl, cycloalkyl, arylalkyl or phenyl group.
Diphosphines of formula (IIb) which correspond to formula (II) in which Xi represents a group -NHRa is obtained by reaction of the dibrominated diphosphine of formula (III) and an amine RaNH2 (Kazankov MV, Ginodman LG, J Org Chem, USSR, 1975, 11, 451) followed by a reduction of the diphosphine in the form of dioxide as previously described.
Another diphosphine group of formula (IIc) in which X 1 represents a hydroxyl group can be used as a monomer. It is obtained from the dibrominated diphosphine in the form of a dioxide of formula (III), according to an aromatic nucleophilic substitution reaction with OH [Fyfe CA in Patai The Chemistry of the Hydroxyl Group, pt.1, Wiley: NY, 1971, p. 83.] followed by a reduction of the diphosphine in the form of dioxide as previously described.
Another diphosphine group of formula (IId) wherein X 1 is a carboxylic or ester group may be used as a monomer.
The conversion of a nitrile function to a carboxylic acid function is described in the basic works of organic chemistry. Also, the skilled person can easily determine the appropriate reaction conditions.
An easy way to proceed is to use as the hydrolysis agent, aqueous sodium hydroxide.
Alternatively, it is possible to convert the two carboxylic functions of the compound of formula (IId) into ester or hydroxymethyl functions.
A diphosphine of formula (IIe) which corresponds to the formula (II) in which Xi represents a group -COORa is obtained by direct esterification of the compound of formula (IId) conventionally carried out in a basic medium followed by a reduction of the diphosphine in the form of dioxide as previously described.
A diphosphine of formula (IIf) which corresponds to the formula (II) in which X1 represents a group -CH20H is obtained by reduction of the compound of formula (IId) using, for example, LiAlH4 or NaH [Gaylord NG, Reduction with complex metals hydride; Wiley: NY, 1956, p. 322] followed by a reduction of the diphosphine in the form of dioxide as previously described.
A diphosphine of formula (IIg) which corresponds to formula (II) in which X1 represents a group -N = C = O is obtained by reaction of the compound of formula (IIb) with phosgene carried out according to the teaching of the literature in particular by Jerry MARCH, Advanced Organic Chemistry, 5th Edition, John Wiley and Sons, p. 507.
A diphosphine of formula (IIh) which corresponds to formula (II) in which X1 represents a group -CH2-N = C = O is obtained by reaction of the compound of formula (IIa) with phosgene.
According to the invention, one of the diphosphines corresponding to one of the formulas (IIa) to (IIh) is reacted with a polymerizable monomer. It is preferentially chosen to implement only one polymerizable monomer.
As classes of monomers, there may be mentioned in particular, diacids, diesters, diols, diisocyanates, dialdehydes or diketones.
Although the invention does not intend to be specifically limited thereto, the polyamides, polyureas and polyimides will be described in more detail.
The polyureas, polyamides and polyimides of the invention may be prepared from a chiral diphosphine consisting of a chiral body bearing, as functional groups, two amino groups or two aminomethyl groups and which corresponds to formulas (IIa) and (He b).
Polyurea.
When the targeted polymer is a polyurea, it may be synthesized by polymerization of a diphosphine bearing two -NH2 or -CH2-NH2 groups with one or more di- or polyisocyanates.
The nature of the isocyanate compound is not critical per se.
Preferably, the diisocyanate is a diisocyanate of formula (Ia):

in which: J represents a divalent hydrocarbon group of aliphatic, alicyclic and / or aromatic nature, the size of the group J will be adjusted by those skilled in the art depending on the end use of the ligand and in particular as a function of the reaction that must catalyze the metal complex formed from this polymeric ligand.
The catalytic sites of the polymer of the invention are located at the units derived from the diphosphine. The size of the group J thus determines the spacing of the catalytic sites.
Group J is for example a C1-C16 alkylene chain, preferably C1-C12, optionally interrupted by one or more (preferably 1 to 4, more preferably 1 to 2) heteroatoms selected from O, N and S, said chain; optionally comprising one or more unsaturations (preferably 1 to 4, more preferably 1 to 2); a - (CH2) aK- (CH2) b- group where a and b are independently an integer of 0 to 6 and K is (C6C8) cycloalkylene; a - (CH2) aL- (CH2) b- group where a and b are as defined above and L is (C6-C10) arylene; a group - (CH 2) a-Vo- (CH 2) b - where a and b are as defined above and Vo is 5 to 8-membered heteroarylene having 1 to 3 heteroatoms selected from O, N and S; still a group -Mo-Q-Mo- in which Mo is selected from (C3-C8) cycloalkylene and (CeC10) arylene and Q represents a bond, a sulfur atom, an oxygen atom, (C1-C4) alkylene ), -SO-, -SO2- or -CO-.
When J contains an alkylene chain, it is linear or branched and preferably has 1 to 6 carbon atoms. When this alkylene chain comprises a nitrogen atom, it carries a (C 1 -C 6) alkyl group or a hydrogen atom.

When J contains cycloalkylene, it is preferred that J be cyclohexylene.
When J contains arylene, it is preferred that J be phenylene or naphthalene.
When J is - (CH2) aL- (CH2) b-, - (CH2) aK- (CH2) b- or - (CH2) a-Vo (CH2) b-, it is preferred that a and b are the same.
By heteroarylene is meant a bivalent group corresponding to a heterocycle in which two hydrogen atoms have been replaced by two bonds.
Heteroarylenes derived from heterocycles: furan, thiophene, pyrrole, oxazole, thiazole, imidazole, pyrrazole, isoxazole, isothiazole, pyridine, pyridazine, pyrimidine, pyrazine, indolizine, indole, isoindole, benzofuran, benzothiophene, benzimidazole, benzothiazole, quinoline, are preferred. isoquinoline, cinnoline, phthalazine, quinazoline, naphthyridine and pteridine. Very advantageously, heteroarylene is derived from imidazole, benzimidazole, pyrimidine or quinazoline.
When J is -Mo-Q-Mo-, it is preferred that Q is (C1-C2) alkylene, a bond, and Mo is cyclohexylene or phenylene.
Group J as defined above may carry one or more substituents chosen from a halogen atom, a C1-C6 alkyl group, a C1-C6 alkoxy group, an oxo group and a di (C1-C6) group. ) alkylamino.
Examples of particularly suitable diisocyanates are: 1,2-diisocyanatopropane, 1,4-diisocyanatobutane, 2,6-diisocyanatotoluene, 1,12-diisocyanatododecane, trans-1,4-cyclohexanediisocyanate, 4,4'-diisocyanatodiphenyl methane, 4,4'-diisocyanato-3,3'-dimethyldiphenylmethane, 1,5-diisocyanatonaphthalene.
The condensation of the diisocyanate with the diphosphine is carried out under appropriate conditions which are easily determined by those skilled in the art.
These polymerization conditions are preferably adjusted to obtain a polymer having a degree of polymerization of from 2 to 100, preferably from 5 to 100, for example from 2 to 50, more preferably from 4 to 25.
Polyureas with a degree of polymerization of 3 to 8 are particularly suitable.
Those skilled in the art will choose the degree of polymerization so that the resulting polymer is insoluble in the solvent or solvent mixtures used in the asymmetric reaction to be catalyzed.
The choice of the polymerization method is not critical according to the invention.
A particularly suitable method is solution polymerization.
The solvent is generally an aprotic polar solvent selected from an optionally halogenated aliphatic hydrocarbon, for example methylene chloride, chloroform, carbon tetrachloride or dichloroethane; an optionally halogenated aromatic hydrocarbon, for example chlorobenzene or dichlorobenzene; an ether such as diethyl ether, diisopropyl ether, tetrahydrofuran, dioxane, diethylene glycol dimethyl ether, glymes and especially 1,2-dimethoxyethane; an amide such as formamide, dimethylformamide, dimethylacetamide, N-methyl-2-pyrrolidinone or hexamethylphosphorylamide; a nitrile such as acetonitrile or isobutyronitrile; and dimethylsulfoxide.
The concentration of the reagents in the solution varies very widely depending on the solubility of the reagents. It is generally between 0.05 and 1 mol / l, preferably between 0.01 and 1 mol / l, for example 0.1 mol / l.
In a preferred manner, the diisocyanate is used in slight excess with respect to the diphosphine, although strictly speaking a stoichiometric ratio of these two compounds may be suitable.
Thus, the molar ratio of diisocyanate to diphosphine is generally set between 1 and 1.5, for example between 1 and 1.3.
The temperature at which the polymerization is carried out is determined according to the reactivity of the different reactants and the desired degree of polymerization. By way of indication, the temperature varies between -20 [deg] C and 100.degree. C., preferably between room temperature and 100.degree. C., for example between 15 and 100.degree. C., better still between 15.degree. 40 [deg] C. Advantageously, it is 20.C.
The polymerization is carried out conventionally by solubilization of the reactants in the solvent, mixing, optionally heating the reaction medium, and then isolating the polymer, for example by filtration of the reaction medium. It will be noted that it may be necessary, before isolation of the polymer, to deactivate the ends of the polymer chain, and in particular the unreacted isocyanate functions, by the addition of a C1-C6 alkanol, for example propanol, isopropanol, methanol, ethanol or even tert-butyl alcohol.
An example of a particularly preferred polymer is a polymer having as recurrent pattern:

in which - R1, R2, which may be identical or different, represent a hydrogen atom or a substituent, - Ar1 and Ar2 independently represent an alkyl, alkenyl, cycloalkyl, aryl or arylalkyl group, - has the meaning given above. the degree of polymerization is preferably between 2 and 100, more preferably between 2 and 50.
Polyamides.
When the polymer is a polyamide, it may be prepared by condensing a chiral diphosphine having two amino or aminomethyl functions with one or more dicarboxylic acids or activated derivatives thereof.
The dicarboxylic acid advantageously corresponds to the following formula (Ib):

wherein W is as defined for J above.
The preferred meanings of J indicated above are also preferred meanings of W.
The group W may be substituted with one or more halogen atoms or oxo, (C 1 -C 6) alkyl, (C 1 -C 6) alkoxy or di (C 1 -C 6) alkylamino groups.
Among these dicarboxylic acids, those having an axis of symmetry C2 such as:
aliphatic acids chosen from: malonic acid, succinic acid, glutaric acid, adipic acid, 2,4-dimethyladipic acid, pimelic acid, suberic acid, - azelaic acid, - sebacic acid, - dodecanedioic acid, - fumaric acid, - maleic acid, - methyliminodiacetic acid, - 3-dimethylaminohexanedioic acid, - acids cycloalkanedicarboxylic acids and especially: 1,4-cyclohexanedicarboxylic acid, aromatic dicarboxylic acids chosen from: phthalic acid, isophthalic acid, terephthalic acid, phenylenediacetic acid, acid 1,5-naphthalenedicarboxylic acid, 4,4'-diphenyldicarboxylic acid, 3,3'-diphenyldicarboxylic acid, 4,4'-dicarboxydiphenylsulfone, 3,3'-dicarboxydiphenylsulfone.
A particularly preferred group of dicarboxylic acids are the following acids: - succinic acid, - adipic acid, - fumaric acid, - isophthalic acid, - terephthalic acid, - acid 1, 5-naphthalenedicarboxylic acid, 4,4'-diphenyldicarboxylic acid, 3,3'-diphenyldicarboxylic acid.
The activated derivative of the dicarboxylic acid more generally denotes the dicarboxylic acid compound in which one or two of the carboxylic functions have been modified so as to increase their reactivity.
Activated derivatives of dicarboxylic acid are for example obtained by forming an anhydride bond or a -COY group where Y is a halogen atom such as bromine or chlorine.
Other activated derivatives of the dicarboxylic acids are those carrying instead carboxylic functions, -COT groups where T denotes an azide group, imidazolide, p-nitrophenoxy, 1-benzotriazole, NO-succinimide, acyloxy (such as pivaloyloxy) (C1-C4) alkoxycarbonyloxy, dialkyl- or dicycloalkyl-O-ureide.
The condensation of the diphosphine with the dicarboxylic acid or its activated derivative is generally carried out in a solvent.
When the dicarboxylic acid is used as such, it may be advantageous to carry out the condensation in the presence of a catalyst, for example a strong acid such as hydrochloric or sulfuric acid or in the presence of a condensing agent. such as those commonly used in peptide synthesis.
Among the known condensing agents, mention may be made of N-hydroxyl derivatives such as N-hydroxysuccinimide and 1-hydroxybenzotriazole; disulfides such as dipyridyl 2,2'-disulfide; succinic acid derivatives such as N, N'-disuccinimidyl carbonate; phosphinic chlorides such as N, N'-bis- (2-oxo-3-oxazolidinyl) phosphinic chloride; oxalates such as N, N'-disuccinimidyl oxalate (DSO), diphthalimide N, N'-oxalate (DPO), N, N'-bis (norbornenylsuccinimidyl) oxalate (BNO), 1,1'bis (benzotriazolyl) oxalate (BBTO), 1,1'-bis (6-chlorobenzotriazolyl) oxalate (BCTO) or 1,1'-bis (6-trifluoromethylbenzotriazolyl) oxalate (BTBO) ); triarylphosphines such as triphenylphosphine, a combination of a di (lower alkyl) azodicarboxylate and a triarylphosphine, such as a combination of diethyl azodicarboxylate and triphenylphosphine; N (lower alkyl) -5-aryl-isoxazolium-3'-sulfonates such as N-ethyl-5-phenylisoxazolium-3'-sulfonate; carbodiimide derivatives, including N ', N'dicycloalkylcarbodiimides such as N', N'-dicyclohexylcarbodiimide (DCC) or 1-ethyl-3- (3-dimethylaminopropyl) carbodiimide (EDAPC); diheteroaryl diselenides such as di-2-pyridyl diselenide; arylsulfonyltriazolides such as p-nitrobenzene sulfonyltriazolide; 2-halo-1 (lower alkyl) pyridinium halides such as 2-chloro-1-methylpyridinium iodide; diarylphosphorylazides such as diphenylphosphorylazide (DPPA), imidazole derivatives such as 1,1'-oxalyldiimidazole or N, N'-carbonyldiimidazole; benzotriazole derivatives such as 1-hydroxybenzotriazole (HOBT); and dicarboximide derivatives such as N-hydroxy-5-norbornene-2,3-dicarboximide (HONB). Of these, the carbodiimide derivatives are preferred.
The reaction can take place in a wide temperature range.
Depending on the reactivity of the reagents put in the presence, the reaction temperature oscillates between -20 [deg] C and 100 [deg] C.
When the polymerization involves the reaction of an activated derivative of the dicarboxylic acid with a diphosphine, a relatively low temperature, preferably between 0 [deg] C and 40 [deg] C, is sufficient.
Conversely, when the dicarboxylic acid as such is involved in the reaction, the temperature is preferably between 50 and 80 [deg.] C.
The concentration of the reagents in the reaction medium is not critical according to the invention. It can vary between 0.05 and 1 mol / l.
In general, the molar ratio of the dicarboxylic acid or its activated derivative to diphosphine varies between 0.8 and 1.5, preferably between 0.9 and 1.2.
A typical procedure, illustrating the preparation of a polyamide from a carboxylic acid chloride, is as follows.
To a solution of 4.16 mmol of diphosphine in 5 ml of N, N-dimethylacetamide is added 3.75 mmol of the carboxylic acid chloride. The reaction mixture is stirred overnight at room temperature (18 ° to 30 ° C.). The polyamide is then precipitated in 150 ml of distilled water. The polymer is filtered on sintered glass, washed with water and then with isopropanol.
The general conditions for carrying out polymerization and for isolating the polymer will be easily determined by those skilled in the art, it being understood that the preferred polyamides of the invention have a degree of polymerization of between 2 and 100, for example between 5 and 100, preferably between 2 and 50, more preferably between 4 and 25.
Those skilled in the art will choose the degree of polymerization so that the resulting polymer is insoluble in the solvent or solvent mixtures used in the asymmetric reaction to be catalyzed.
An example of a preferred polymer is a polymer having as recurrent pattern:

in which - R1, R2, which are identical or different, represent a hydrogen atom or a substituent, - Ar1 and Ar2 independently represent an alkyl, alkenyl, cycloalkyl, aryl or arylalkyl group, - W has the meaning given for J, - the degree the polymerization being preferably between 2 and 100, more preferably between 2 and 50.
Polyimides.
When the polymer is a polyimide, it may be prepared by condensation of a chiral diphosphine bearing two amino or aminomethyl functions with one or more tetracarboxylic acids or tetracarboxylic acid dianhydrides.
For the preparation of these polyimides, a person skilled in the art can draw inspiration from DC Sherrington, Chem. Common, 1998, 2275-2286.
Advantageously, the polyimides are prepared in two stages.
In a first step, a polyamide is formed. This step is, for example, carried out at a temperature of between 15 and 50.degree. C., preferably between 20.degree. And 30.degree. C., in a polar aprotic solvent (such as a formamide-type amide, dimethylacetamide, N-methyl-2-pyrrolidinone, preferably dimethylacetamide).
In a second step, the polyimide is formed. This second step can be carried out by treatment with a mixture of acetic anhydride and pyridine at a temperature between -100 [deg] C and 10 [deg] C, preferably between -78 and -50 [deg] C.
According to another variant of the invention, the polymer may be a polyurethane.
Polyurethanes When the polymer is a polyurethane, it can be prepared by condensing a chiral diphosphine bearing two hydroxyl or hydroxymethyl groups with a diisocyanate monomer.
In this case, tin salt catalysis is often necessary. One can refer in particular to the article by M. Lemaire et al. J. Mol. Cat. A. 2002, Vol. 182-183, 239-247.
According to one of its aspects, the invention therefore relates to a process for the preparation of a polymer of the invention comprising the polymerization of a chiral diphosphine of formula (II), preferably (la) to (IIh) with one or a plurality of polymerizable monomers, preferably of formula (I); said chiral phosphine consisting of a chiral body bearing two identical functional groups capable of reacting with said polymerizable monomers.
The invention also relates to the racemic polymer corresponding to the optically active polymer of the invention.
This polymer can be prepared simply by polymerizing the appropriate diphosphine with one or more polymerizable monomers, said diphosphine carrying two identical functional groups capable of reacting with said polymerizable monomers.
Preferably, the diphosphines used in this reaction are the racemic diphosphines corresponding to the preferred chiral diphosphines defined above. Thus, according to a preferred embodiment of the invention, the racemic diphosphine consists of a racemic base skeleton of formula (IIa) to (IIh) carrying two identical functional groups.
Similarly, the polymerizable monomers preferably used for this polymerization are those described above for the preparation of optically active polymers.
The operating conditions of this polymerization will be easily determined by those skilled in the art by analogy to those proposed for the polymerization reaction leading to the optically active polymer.
The polymers of the invention can be used as ligands for the preparation of metal complexes for the asymmetric catalysis of hydrogenation, hydrosilylation, hydroboration of unsaturated compounds, epoxidation of allyl alcohols, vicinal hydroxylation reactions. , hydrovinylation, hydroformylation, cyclopropanation, isomerization of olefins, propylene polymerization, addition of organometallic compounds to aldehydes, allylic alkylation, aldol reactions, Diels- Alder and, in general, CC bond formation reactions (such as allylic substitutions or Grignard cross-couplings).
According to a preferred embodiment of the invention, the complexes are used for the hydrogenation of the bonds C = O, C = C and C = N.
An object of the invention is therefore new complexes comprising the optically active polymer as defined above and a transition metal.
Examples of transition metals capable of forming complexes include metals such as rhodium, ruthenium, rhenium, iridium, cobalt, nickel, platinum and palladium.
Of the above metals, rhodium, ruthenium and iridium are preferred.
Thus, according to another of its aspects, the invention relates to the use of the polymer of the invention for the preparation of a metal complex of a transition metal intended for asymmetric catalysis, and more particularly of a complex of ruthenium, iridium or rhodium.
Specific examples of said complexes of the present invention are given below, without limitation.
In the following formulas, Pp represents the polymer.
A preferred group of rhodium and iridium complexes is defined by the formula:

in which: - Pp represents a ligand according to the invention; Y1 represents a coordinating anionic ligand; - Me represents iridium or rhodium; and - Lig represents a neutral ligand.
Among these compounds, the ligands that are particularly preferred are those in which: L 1 represents an olefin having from 2 to 12 carbon atoms; Y represents anion PF6-, PC16-, BF4-, BC14-, SbF6-, SbCl5, BPh4-, ClO4-, CN-, CF3SO3, halogen, preferably C1- or Br, anion 1,3-diketonate alkylcarboxylate, haloalkylcarboxylate with a lower alkyl group (preferably C1-C6), a phenylcarboxylate anion or phenolate whose benzene ring may be substituted by lower (preferably C1-C6) alkyl groups and / or halogen.
In the formula (Fi), Lig2 can represent two Lig ligands as defined above or a bidentate ligand such as bident ligand, linear or cyclic, polyunsaturated and comprising at least two unsaturations.
It is preferred according to the invention that Lig2 represents 1,5-cyclooctadiene, norbornadiene or that Lig represents ethylene.
By lower alkyl groups is generally meant a linear or branched alkyl group having 1 to 4 carbon atoms.
Other iridium complexes are those of formula:

wherein Lig, Pp and Y are as defined for formula (Fi).

A preferred group of ruthenium complexes are compounds of the formula:

in which: - Pp represents a ligand according to the invention; YI and YI, which are identical or different, represent anion PF6-, PC16-, BF4-, BC14-, SbF6-, SbCls, BPh4-, ClO4-, CF3SO3, a halogen atom, more particularly chlorine or bromine or a carboxylate anion, preferably acetate, trifluoroacetate.
Other ruthenium complexes are those corresponding to the following formula (F4):

in which: - Pp represents a ligand according to the invention; ar represents benzene, p-methylisopropylbenzene or hexamethylbenzene; YI3 represents a halogen atom, preferably chlorine or bromine; Y1 4 represents an anion, preferably an anion PF6-, PC16-, BF4-, BC14-, SbF6-, SbCl6-, BPh4, ClO4-, CF3SO3.
It is also possible to implement in the process of the invention complexes based on palladium and platinum.
As more specific examples of said complexes, there may be mentioned among others Pd (hal) 2Pp and Pt (hal) 2PP where Pp represents a ligand according to the invention and hal represents halogen such as, for example, chlorine.
The complexes comprising a ligand according to the invention and the transition metal may be prepared according to the known processes described in the literature.
The complexes are generally prepared from a precatalyst whose nature varies according to the selected transition metal.
In the case of rhodium complexes, the precatalyst is for example one of the following compounds: [Rh 1 (CO) 2 Cl] 2; [Rh1 (COD) C1] 2 wherein COD is cyclooctadiene; or Rh '(acac) (CO) 2 where acac is acetylacetonate.
In the case of ruthenium complexes, especially suitable precatalysts are bis- (2-methylallyl) -cycloocta-1,5-diene ruthenium and

By way of example, starting from bis- (2-methylallyl) -cycloocta-1,5-diene ruthenium, a solution or suspension containing the metal precatalyst, a ligand and a perfectly degassed solvent such as acetone ( the ligand concentration of the solution or suspension varying between 0.001 and 1 mol), to which a methanolic solution of hydrobromic acid is added. The ratio of ruthenium to bromine preferably ranges from 1: 1 to 1: 4, preferably from 1: 2 to 1: 3. The molar ratio of the ligand to the transition metal is about 1. It can be between 0.8 and 1.2.
When the precatalyst is [RuCl 2 (benzene)] 2, the complex is prepared by mixing the precatalyst, the ligand and an organic solvent and optionally maintaining a temperature of between 15 and 150 ° C. for 1 minute to 24 hours. preferably 30 to 120 [deg.] C for 10 minutes to 5 hours.
As a solvent, mention may be made of aromatic hydrocarbons (such as benzene, toluene and xylene), amides (such as formamide, dimethylformamide, dimethylacetamide, N-methyl-2-pyrrolidinone or hexamethylphosphorylamide), alcohols (such as ethanol, methanol, n-propanol and isopropanol) and mixtures thereof.
Preferably, when the solvent is an amide, in particular dimethylformamide, the mixture of the ligand, the precatalyst and the solvent is heated to between 80 and 120.degree.
Alternatively, when the solvent is a mixture of an aromatic hydrocarbon (such as benzene) with an alcohol (such as ethanol), the reaction medium is heated to a temperature between 30 and 70 [deg.] C.
The catalyst is then recovered according to conventional techniques (filtration or crystallization) and used in asymmetric reactions. Nevertheless, the reaction to be catalyzed by the complex thus prepared can be carried out without intermediate isolation of the catalyst complex.
In the following, the case of hydrogenation is described in detail.
The unsaturated substrate, dissolved in a solvent comprising the catalyst, is placed under hydrogen pressure.
The hydrogenation is for example carried out at a pressure ranging between 1.5 and 100 bar, and at a temperature between 20 [deg] C and 100 [deg] C.
The exact conditions of implementation depend on the nature of the substrate to be hydrogenated. Nevertheless, in the general case, a pressure of 20 to 80 bar, preferably 40 to 60 bar, and a temperature of 30 to 70.degree. C., are particularly suitable.
The reaction medium may consist of the reaction medium in which the catalyst has been obtained. The hydrogenation reaction then takes place in situ.
Alternatively, the catalyst is isolated from the reaction medium in which it was obtained. In this case, the reaction medium of the hydrogenation reaction consists of one or more solvents, in particular chosen from C 1 -C 5 aliphatic alcohols, such as methanol or propanol, and an amide as defined above. preferably dimethylformamide, optionally in admixture with benzene.
When the hydrogenation reaction takes place in situ, it is desirable to add to the reaction medium one or more solvents chosen from those mentioned above, and more particularly one or more aliphatic alcohols.
According to a preferred embodiment, the reaction medium containing the complex is admixed with perfectly degassed methanol and the substrate. The quantity of methanol, or more generally of solvent, that can be added is such that the concentration of the substrate in the hydrogenation reaction medium is between 1 × 10- and 10 mol / l, preferably between 0.01 and 1 mol / l. .
The molar ratio of the substrate to the catalyst generally varies from 1: 100 to 1: 100,000, preferably from 1: 20 to 1: 2,000. This ratio is for example 1/1000.
Removal of the catalyst from the reaction medium is facilitated by the insolubility characteristics of the catalyst.
The catalyst is separated from the reaction medium by nanofiltration or ultrafiltration.
The nanofiltration technique is more particularly suitable for the case of polymer type catalysts. The application of this technique is for example illustrated in Tetrahedron: Asymmetry, vol. 8, n [deg] 12, 1975-1977, 1997.
An advantage of the process of the invention is that the recovered catalyst can be easily recycled without loss of activity.
The ruthenium, rhodium and iridium complexes prepared from the polymeric ligands of the invention are especially suitable for asymmetric catalysis of asymmetric hydrogenation reactions.
The ruthenium complexes prepared from the polymeric ligands of the invention are more especially suitable for asymmetric catalysis of hydrogenation reactions of C = O bonds, C = N bonds. C = C bonds and preferably C = C bonds of α, β-ethylenic carboxylic acids.
As for the hydrogenation of double bonds, the appropriate substrates are of the α, β-unsaturated carboxylic acid type and / or α, unsaturated carboxylic acid derivatives. These substrates are described in EP 95943260.0.
The alpha, beta-unsaturated carboxylic acid and / or its derivative more particularly corresponds to formula A:

in which: - R1, R2, R3 and R4 represent a hydrogen atom or any hydrocarbon group, insofar as:. if R1 is different from R2 and different from a hydrogen atom then R3 can be any hydrocarbon or functional group designated R1. if R 1 or R 2 represents a hydrogen atom and if R 1 is other than R 2, then R 3 is different from a hydrogen atom and different from -COOR 4, if R 1 is identical to R 2 and represents any hydrocarbon or functional group designated R, then R 3 is different from -CH- (R) 2 and different from -COOR 4 - one of R 1, R 2 and R 3 may represent a functional group.
As a specific example, mention may be made inter alia of 2-methyl-2-butenoic acid.
A first group of preferred substrates is formed by the amino acid and / or derivative precursor substituted acrylic acids.
By the term "substituted acrylic acids" is meant all the compounds whose formula is derived from that of acrylic acid by substitution of at most two of the hydrogen atoms carried by the ethylenic carbon atoms by a hydrocarbon group or by a functional group.
They can be symbolized by the following chemical formula:

in which: R9, R'9, identical or different, represent a hydrogen atom, a linear or branched alkyl group having from 1 to 12 carbon atoms, a phenyl group or an acyl group having from 2 to 12 carbon atoms; carbon, preferably an acetyl or benzoyl group; - R8 represents a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, a cycloalkyl group having 3 to 8 carbon atoms, an arylalkyl group having 6 to 12 carbon atoms, an aryl group having 6 to 12 carbon atoms, a heterocyclic group having 4 to 7 carbon atoms, - R10 represents a hydrogen atom or a linear or branched alkyl group having from 1 to 4 carbon atoms.
Mention may more particularly be made of: methyl α-acetamidocinnamate, methyl acetamidoacrylate, benzamidocinnamic acid, α-acetamidocinnamic acid.
A second preferred group of substrates consists of itaconic acid and its derivatives of formula:

in which: R 11, R 12, which may be identical or different, represent a hydrogen atom, a linear or branched alkyl group having from 1 to 12 carbon atoms, a cycloalkyl group having from 3 to 8 carbon atoms, an arylalkyl group having 6 to 12 carbon atoms, an aryl group having 6 to 12 carbon atoms, a heterocyclic group having 4 to 7 carbon atoms. - R10, R'10, identical or different, represent a hydrogen atom or a linear or branched alkyl group having from 1 to 4 carbon atoms.
More specific examples that may be mentioned include itaconic acid and dimethyl itaconate.
A third preferred group of substrates is defined by the formula (A3):

in which: R "represents a hydrogen atom or a linear or branched alkyl group having from 1 to 4 carbon atoms; R13 represents a phenyl or naphthyl group optionally carrying one or more substituents.
As specific examples, mention may be made of the substrates leading, by hydrogenation, to 2- (3-benzoylphenyl) propionic acid (ketoprofen), 2- (4-isobutylphenyl) propionic acid (ibuprofen), 2- (5 Methoxynaphthylpropionic (Naproxen).
With regard to the hydrogenation of carbonyl bonds, the ruthenium complexes are more particularly suitable for the asymmetric catalysis of the hydrogenation reactions of the C = O bonds of p-ketoesters, α-keto esters or ketones.
Suitable ketone substrates more preferably correspond to formula (B):

in which: - R14 is different from R15, - R14 and R15 represent a hydrocarbon group having 1 to 30 carbon atoms optionally comprising one or more functional groups, - R14 and R15 may form a ring optionally comprising another heteroatom.
These compounds are precisely described in FR 96 08 060 and EP 97930607.3.
A preferred group of ketonic compounds corresponds to the formula (B) in which R14 and R15 represent, independently of one another: an alkyl chain, preferably a C 1 -C 10 chain, optionally interrupted by one or more atom (s) oxygen or sulfur or carbonyl function (s) and optionally substituted by one or more halogen atoms or carboxyl groups, an alkenyl or alkynyl chain, preferably a C2 to C10 chain, optionally interrupted by one or more atoms (s). ) oxygen or sulfur or carbonyl function (s) and optionally substituted with one or more halogen atom (s) or carboxyl group (s); an aryl group, preferably a C6-C12 group, optionally substituted by one or more halogen atoms or an alkyl or alkenyl group (s); an arylalkyl group, preferably a C6-C15 group, optionally substituted with a or more halogen atom (s); an arylalkenyl group, preferably C8 to C15, optionally substituted by one or more halogen atom (s); and - * indicates the possible presence in R2 of an asymmetric center located in position a of the carbonyl function.
As a representative of the substituents R15 having a center of asymmetry, there may be mentioned especially the groups R15, the carbon atom bearing the center of asymmetry is substituted by a mono- or disubstituted amine function and by an ester function.
According to a particularly preferred embodiment of the invention, the substrate is a β-ketoester (such as ethyl acetoacetate or methyl 3-oxovalerate), α-ketoester (such as methyl benzoylformate or methyl pyruvate), a ketone (such as acetophenone), or an α, éthyl-ethylenic carboxylic acid (such as itaconic acid) or an unsaturated amino acid or a derivative thereof (such as methyl 2-acetamidoacrylate) .
The invention furthermore relates to the use of the combination of an optically active polymer according to the invention with a diamine, chiral or otherwise, for the selective reduction of ketones.
Advantageously, a chiral diamine is used in this combination.
The diamines that can be used for this purpose are the optically active diamines described in WO 97/20789 and the corresponding racemic diamines.
According to a particularly preferred embodiment of the invention, the diamine is 1,2-diamino-1,2-diphenylethane; 1,1-bis (p-methoxyphenyl) -2-methyl-1,2-diaminoethane; 1,1-bis (p-methoxyphenyl) -2-isobutyl-1,2-diaminoethane; or 1,1-bis (p-methoxyphenyl) -2-isopropyl-1,2-diaminoethane.
Examples of chiral diamines are more particularly those of formula:

wherein G4 is alkyl, for example methyl, isobutyl or isopropyl.
Non-chiral ethylenediamine and non-chiral or chiral 1,2-diamino-1,2-diphenylethane, such as R, R-1,2-diamino-1,2-diphenylethane, are more particularly mentioned.
The ketones that can be reduced by this process are those described above.
The conditions for carrying out the reduction are those generally described above.
The invention further relates to the use of the combination of a racemic polymer according to the invention with a chiral diamine for the selective reduction of ketones.
The chiral diamine which can be used is as described in WO 97/20789, the ketones and the operating conditions being as defined above.
The rhodium complexes prepared from the polymeric ligands of the invention are especially suitable for asymmetric catalysis of olefin isomerization reactions.
The examples which follow illustrate more precisely the invention.
The meaning of the abbreviations used is given below.

Example 1

Preparation of 4,4'-diaminomethyl IBINAP:
Preparation of BINAPO:
In a 250 ml flask, the (S) - or (R) -BINAP (2,2'bis (diphenylphosphino) -1,1'-binaphthyl) (3 g, 4.81 mmol, 1 eq.) Is dissolved. in 100 mL of CH2Cl2.
It is cooled to 0 ° C. and 10 ml of 35% by weight hydrogen peroxide are added.

Stirring is allowed to return to ambient temperature for 4 hours.
100 ml of water are then added.
The organic phase is separated off and the aqueous phase is extracted with CH 2 Cl 2.
The combined organic phases are washed with saturated sodium bisulfite.
The absence of peroxide is checked and then dried over sodium sulphate and evaporated.
A white solid is obtained (m = 3.14 g, 4.8 mmol, quantitative yield).
The characterization of the diphosphine in the form of dioxide (BINAPO) is as follows: H-NMR (300 MHz, CDCl3): 6.80 (d, 4H, J = 3.7), 7.2-7.3 (m , 8H), 7.3-7.5 (m, 12H), 7.6-7.7 (m, 4H), 7.8-7.9 (m, 4H). P NMR (81 MHz, CDCl3): 28.67 - mp: 256-258 [deg.] C.
Preparation of 4,4'-dibromoBINAPO
In a 250 mL dry flask, BINAPO (5 g, 7.64 mmol, 1 eq.) Dissolved in 150 mL of dichloromethane was placed.
Pyridine (0.62 mL, 7.64 mmol, 1 eq) and then dibroma (1.2 mL, 22.92 mmol, 3 eq) are then added.
Stirred at room temperature for 20 hours.
Transfer to a separatory funnel and then treated successively with saturated sodium bisulfite, brine and saturated sodium bicarbonate.
It is dried over sodium sulphate and evaporated.
The procedure is repeated twice.
The product is recrystallized from methanol to obtain a white solid (m = 4.74 g, 5.8 mmol, ie a yield of 76%).
The characterization of the dibrominated diphosphine is as follows: H-NMR (300 MHz, CDCl3): 6.80 (d, 2H, J = 8.3, 8.8'H), 6.85 (ddd, 2H) , J = 0.9, 6.7, 15.1, 7.7'H), 7.2-7.5 (m, 18H, phenyl + H6 and H6 '), 7.6-7.7 (m 4H, phenyl), 7.75 (s, 2H, 3.3'H), 8.23 (d, 2H, J = 8.4, 5.5H) - P-NMR (81 MHz, CDCl 3) : 27.60 - Mp:> 300 [deg] C Preparation of 4,4'-dicyanoBINAPO:
Under an inert atmosphere, in a 50 mL flask equipped with a condenser, was placed 4,4'-dibromoBINAPO (200 mg, 0.25 mmol, 1 eq) and copper cyanide (63 mg, 0.7 mmol, 2.8 eq.).
The mixture is dissolved in 3 mL of DMF and refluxed overnight.
The mixture is cooled and then treated with a solution of ethylenediamine (1 mL) and water (1 mL).
Stirred for 2 minutes and then added 5 mL of water and 10 mL of toluene.
The mixture is stirred for 5 minutes and then the aqueous phase is extracted once with toluene.
The combined organic phases are washed successively with 1 time of water, 4 times of HCl (0.1 M), 1 time of the brine, then 1 time with saturated sodium bicarbonate.
The product is then dried over sodium sulphate and then evaporated under reduced pressure (approximately 8 mm Hg).
The solid obtained is recrystallized from methanol.
A white and pure solid is obtained (m = 0.100 g, 0.15 mmol, ie a yield of 60%).
The characterization of the diphosphine (PO) in dicyan form is as follows: 1 H NMR (200 MHz, CDCl 3): 6.73 (d, 2H, J = 8.4), 6.90 (ddd, 2H, J = 1.0, 7.0, 14.3), 7.2-7.8 (m, 22H), 7.85 (d, 2H, J = 11.3), 8.28 (d, 2H, 8). , 3). NMR P (81 MHz, CDCl3): 27.77 - Mass (ESI +): MH + = 813.35 - Tf:> 300 [deg] C Preparation of 4,4'-dicyanoBINAP:
Under an inert atmosphere in a dry 25 mL flask equipped with a refrigerant, was placed 4,4'-dicyanoBINAPO (420 mg, 0.6 mmol).
Phenylsilane (8 mL, 64.8 mmol) is added and the suspension is degassed under reduced pressure (about 8 mm Hg) and argon is introduced.
The mixture is heated to 130 ° C. and then the trichlorosilane is added in 3 portions (3 × 1 ml) after 1 hour, 3 hours and 15 hours; then stirred for another 2 hours.

Cool and then evaporate the product until a white solid.
This solid is washed with cyclohexane, filtered on Millipore and then dried under reduced pressure (approximately 8 mm Hg).
The pure products (S) or (R) are obtained in quantitative yields.
The characterization of the diphosphine in dicyan form is as follows: 1 H NMR (300 MHz, CDCl 3): 6.64 (d, 2H, J = 9), 6.93-6.97 (m, 2H), 7, 1-7.3 (m, 20H), 7.54 (t, 2H), 7.98 (s, 2H), 8.23 (d, 2H, J = 8.3) - 31 P NMR (81 MHz, CDCl3): -13.30.
Preparation of 4,4'-diaminomethylBINAP:
In a 100 ml flask under an argon atmosphere, 4,4'dicyanoBINAP (400 mg, 0.6 mmol) is placed.
The product is dissolved in a mixture (1: 1) of 22.5 mL of THF and 22.5 mL of toluene.
LiAlH4 (227.7 mg, 6 mmol) is then added portionwise.
It is heated at 105 ° C. for 2 hours.
It is then cooled and 0.5 ml of water and 0.5 ml of a sodium hydroxide solution (15% by weight) are added.
After stirring for 3 minutes, 1.5 g of celite are added.
After 5 minutes, the mixture is then filtered and the residue is washed with dichloromethane.
The filtrate is evaporated and then dried under reduced pressure (approximately 8 mm Hg) to obtain a yellow-white solid.
The product is obtained with a quantitative yield.

Example 2
The characterization of the diphosphine in diaminomethyl form is as follows: H-NMR (200 MHz, CDCl3): 1.56 (s, 4H), 4.33 (s, 4H), 6.7-7.0 (m, 4H), 7.1-7.3 (m, 20H), 7.4-7.5 (m, 4H), 8.08 (d, 2H, J = 8.5)) - 31P NMR (81 MHz CDCl3):? 14.62; C NMR (50 MHz, CDCl3): 44.33; 123.08; 125.64; 126.86; 127.64; 128.03; 128.10; 128.46; 128.65; 128.82; 129.08; 131.26; 132.71; 132.91; 133.00; 133.97; 134.40; 138.87. - alpha D (c = 1, DMF): -102.4 for the (S) -alpha D (c = 1, DMF): +101.7 for the (R) Preparation of a polyurea starting from (S) -4,4'-diaminomethylBINAP (diamBINAP).
In a 10 ml flask, the starting diamBINAP (200 mg, 0.29 mmol) is placed.
This is dissolved in 2 mL of degassed anhydrous dichloromethane.

2,6-Diisocyanatotoluene (51 mg, 0.29 mmol) is added under argon.
The solution is stirred for 12 hours and then 2 mL of degassed isopropanol are added.
The solid is filtered and then washed with isopropanol.
240 mg of polymer (yellow powder) is obtained, ie a yield of 96%.
The characterization of the 4,4'-polyNAP obtained is as follows: - [alpha D] = -101 [deg] (c = 0.410 DMF) - 1 H NMR (DMSO, 200 MHz): 1.03 (d, CH 3); 1.23 (d, CH 3); 2.03 (m, CH 3 tolyl); 3.34 (s, CH 2); 6.66 (d, CH); 6.70-7.50 (m); 7.61 (s, CH); 8.16 (d, CH). 31 P NMR (DMSO, 81 MHz): -16.08.

Example 3
Preparation of a ruthenium catalyst starting from the polymer prepared in Example 2
In a dry 5 mL conical bottom glass reactor maintained under an inert atmosphere and equipped with a stirrer, the polymer and the metal precalyst, bis (2-methylallyl) cycloocta-1,5-diene ruthenium, are weighed in a polymer / metal molar ratio 1: 1.
2 mL of anhydrous and degassed acetone are added and the suspension is stirred for 30 minutes.
A solution of hydrobromic acid at 48% by weight in a Ru / Br ratio of 1: 2.3) is then added.
The solution is then dyed in dark orange.
This solution is stirred for 1 hour and then evaporated.
The catalyst is then obtained in the form of a brown solid.

Example 4
Hydrogenation of ethyl acetoacetate with the aid of the catalyst prepared in Example 3
Anhydrous and degassed ethanol is added to the reactor where the catalyst has just been prepared.
The substrate is then added (in a defined catalyst / substrate ratio).
The reactor is placed in an autoclave under 40 bar of hydrogen pressure and 50.degree.
Stirring is maintained overnight.
The reactor is recovered and then centrifuged.
The supernatant solution is recovered and analyzed by gas chromatography.
The determination of the enantiomeric excesses is carried out by chiral gas chromatography on a Lipodex A 25m x 0.25mm column.
The results obtained are reported in the following table:

Hydrogenation of ethyl acetoacetate leads to ethyl 3-hydroxybutyrate.

Example 4
Hydrogenation of 2-methylacetamidoacrylate using the catalyst prepared in Example 3
Anhydrous and degassed ethanol is added to the reactor where the catalyst has just been prepared.
The substrate is then added (in a defined catalyst / substrate ratio).
The reactor is placed in an autoclave under 40 bar of hydrogen pressure and 50.degree.
Stirring is maintained for 6 hours.
The reactor is recovered and then centrifuged.
The supernatant solution is recovered and analyzed by gas chromatography.
The determination of the enantiomeric excesses is carried out by chiral gas chromatography on a P-dex column at 60 m × 0.25 mm.
The results obtained are reported in the following table:

1 - Diphosphine that can be used as ligand and insolubilized in the form of an optically active polymer obtainable by polymerization of a chiral diphosphine with one or more polymerizable monomers characterized in that said chiral diphosphine consisting of a body chiral bearing two identical functional groups capable of reacting with said polymerizable monomers, corresponds to the following formula:

in said formula: - R1, R2, which are identical or different, represent a hydrogen atom or a substituent, - Ar1 and Ar2 independently represent an alkyl, alkenyl, cycloalkyl, aryl or arylalkyl group, - Xi represents a functional group chosen from groups : amino, aminomethyl, hydroxy, hydroxymethyl, carboxylic, ester, isocyanato, isocyanatomethyl.

Claims (28)

2 - insolubilized diphosphine according to claim 1 characterized in that the diphosphine corresponds to the formula (II) wherein Ar1, Ar2 independently represent a phenyl group optionally substituted by one or more (C1-C6) alkyl or (C1-C6) alkoxy; or a (C4-C8) cycloalkyl group optionally substituted with one or more (C1-C6) alkyl groups. 3 - insolubilized diphosphine according to one of claims 1 and 2 characterized in that the diphosphine corresponds to formula (II) wherein Ar1 and Ar2 are independently selected from phenyl optionally substituted by methyl or tert-butyl; and (C5-C6) cycloalkyl optionally substituted by methyl or tert-butyl. 4 - insolubilized diphosphine according to any one of claims 1 to 3 characterized in that the diphosphine corresponds to formula (II) wherein Ari and Ar2 are identical and preferably represent optionally substituted phenyl. 5 - insolubilized diphosphine according to any one of claims 1 to 4, characterized in that the diphosphine corresponds to formula (II) in which R 1, R 2 represent a hydrogen atom, one or more groups chosen from (C 1 -C 6) ) alkyl and (C1-C6) alkoxy. 6 - insolubilized diphosphine according to any one of claims 1 to 5, characterized in that the diphosphine corresponds to formula (II) wherein R 1, R 2 represent a hydrogen atom.  7 - insolubilized diphosphine according to claim 1 characterized in that the monomer reacted with the diphosphine has the following formula (I):  in which : M represents a divalent hydrocarbon group with aliphatic, alicyclic and / or aromatic character, X 2 represents a functional group, preferably a carboxylic, ester, hydroxy, amino, isocyanato, aldehyde or ketone group. 8 - insolubilized diphosphine according to claim 7, characterized in that the monomer reacted corresponds to formula (I) in which M represents a C1-C12, preferably C1-C6 alkylene chain; a cycloalkylene group, preferably cyclohexylene; an arylene group, preferably phenylene, tolylene or naphthalene. 9 - optically active polymer comprising the following recurring unit:  in which R 1, R 2, which are identical or different, represent a hydrogen atom or a substituent, Ar1 and Ar2 independently represent an alkyl, alkenyl, cycloalkyl, aryl or arylalkyl group; M represents a divalent hydrocarbon group of aliphatic, alicyclic and / or aromatic nature, Fi represents the functional group resulting from the reaction: of the group X 1 selected from the groups: amino, aminomethyl, hydroxy, hydroxymethyl, carboxylic, ester, isocyanato, isocyanatomethyl, and X2 group selected from carboxylic, ester, hydroxy, amino, isocyanato, aldehyde, ketone, the degree of polymerization is preferably between 2 and 100, more preferably between 2 and 50. 10 - Polymer according to claim 9, characterized in that it corresponds to the formula (P) in which M represents a C1-C12, preferably C1-C6 alkylene chain; a cycloalkylene group, preferably cyclohexylene; an arylene group, preferably phenylene, tolylene or naphthalene. 11 - Polymer according to one of claims 9 and 10 characterized in that it corresponds to the formula (P) in which Fi represents: a urea group (Fi) resulting from the reaction of an amino or aminomethyl group (Xi) with an isocyanato group (X2) or an isocyanato or isocyanatomethyl group (X1) with an amino group (X2), a urethane group (F1) resulting from the reaction of an isocyanato or isocyanatomethyl (Xi) group with a hydroxyl group (X2) or a hydroxyl or hydroxymethyl group (Xi) with an isocyanato group (X2), an ester group (F1) resulting from the reaction of a carboxylic or ester group (Xi) with a hydroxyl group (X2) or a hydroxyl or hydroxymethyl group (Xi) with a carboxylic or ester group (X2), an amide group (F1) resulting from the reaction of a carboxylic group (X1) with an amino group (X2) or an amino or aminomethyl group (X1) with a carboxylic group (X2), an imine group (F1) resulting from the reaction of an amino or aminomethyl group (Xi) with an aldehyde or ketone group (X2). 12 - Polymer according to one of claims 9 to 11 characterized in that the polymer is a polyurea, polyamide, polyimide, polyimine, polyester, polyurethane. 13 - Process for preparing the optically active polymer described in one of claims 9 to 12, characterized in that a chiral diphosphine of formula (II) and one or more monomers of formula (1) are polymerized. 14 - Polymer according to claim 9, characterized in that it is a polyurea type polymer having the recurring pattern:  in which R 1, R 2, which are identical or different, represent a hydrogen atom or a substituent, Ar1 and Ar2 independently represent an alkyl, alkenyl, cycloalkyl, aryl or arylalkyl group; J represents a divalent hydrocarbon group of aliphatic, alicyclic and / or aromatic nature, the degree of polymerization is preferably between 2 and 100, more preferably between 2 and 50. 15 - Polymer according to claim 14 characterized in that the degree of polymerization is between 4 to 25, preferably 3 to 8. 16 - Process for the preparation of the polyurea according to one of Claims 14 and 15, characterized in that a diphosphine bearing two groups is polymerized. -NH2 or -CH2-NH2 with one or more di- or polyisocyanates. 17 - Process according to claim 16 characterized in that the diisocyanate is a diisocyanate of formula (la):  in which : J represents a divalent hydrocarbon group of aliphatic, alicyclic and / or aromatic nature. 18 - Polymer according to claim 9 characterized in that it is a polyamide type polymer having the recurring pattern:  in which R 1, R 2, which are identical or different, represent a hydrogen atom or a substituent, Ar1 and Ar2 independently represent an alkyl, alkenyl, cycloalkyl, aryl or arylalkyl group; W represents a divalent hydrocarbon group with aliphatic, alicyclic and / or aromatic character, the degree of polymerization is preferably between 2 and 100, more preferably between 2 and 50. 19 - Process for the preparation of the polyamide according to claim 18 characterized in that one polymerizes a diphosphine bearing two -NH2 or CH2-NH2 groups with a dicarboxylic acid. 20 - Process according to claim 19, characterized in that the dicarboxylic acid advantageously corresponds to the following formula (Ib):  in which : W represents a divalent hydrocarbon group with an aliphatic, alicyclic and / or aromatic character. 21 - Polymer according to one of claims 9 to 12, 14, 18 characterized in that the diphosphine has the formula (II) wherein Ar1, Ar2 independently represent a phenyl group optionally substituted by one or more (C1-C6) ) alkyl or (C1-C6) alkoxy; or a (C4-C8) cycloalkyl group optionally substituted with one or more (C1-C6) alkyl groups. 22 - Polymer according to claim 21, characterized in that Ar1 and Ar2 are independently selected from phenyl optionally substituted with methyl or tert-butyl; and (C5-C6) cycloalkyl optionally substituted by methyl or tert-butyl. 23 - Polymer according to claim 21 characterized in that Ar1 and Ar2 are identical and preferably represent optionally substituted phenyl. 24 - Polymer according to one of claims 21 to 23, characterized in that the diphosphine corresponds to formula (II) in which R1, R2 represent a hydrogen atom, one or more groups chosen from (C1-C6) alkyl and (C1C6) alkoxy. 25 - Polymer according to claim 24 characterized in that R1, R2 represent a hydrogen atom. 26 - Complex of a transition metal comprising at least one polymeric ligand as defined in one of claims 9 to 12, 14, 15, 18, 21 to 25. 27 - Complex according to claim 26 characterized in that the transition metal is selected from: rhodium, ruthenium, rhenium, iridium, cobalt, nickel, platinum, palladium. 28 - Use of an optically active polymer according to one of claims 9 to 12, 14, 15, 18, 21 to 25 as a ligand for the preparation of a metal complex of a transition metal useful in asymmetric catalysis. 29 - Use according to claim 28 characterized in that said complex is intended to catalyze the asymmetric hydrogenation of C = O C = N bonds or C = C bonds. 30 - Use according to one of claims 28 and 29 characterized in that the metal complex is a complex of ruthenium, rhodium or iridium. 31 - Use according to claim 30 characterized in that the metal complex is a complex of ruthenium or rhodium. 32 - racemic polymer corresponding to the polymer according to any one of claims 9 to 12, 14, 15, 18, 21 to 25. 33 - Use of a combination of an optically active polymer according to one of claims 9 to 12, 14, 15, 18, 21 to 25, with a diamine, for the selective reduction of ketones. 34 - Use of a combination of a racemic polymer according to claim 32 with a chiral diamine, for the selective reduction of ketones. 35 - Use according to one of claims 33 and 34 characterized in that the diamine is 1,2-diamino-1,2-diphenylethane.