RU2153499C2 - Method of combined preparation of 1-ethyl-2- phenylalumacyclopropane and 1-ethyl-2,4- diphenylalumacyclopentane - Google Patents

Abstract

FIELD: chemical industry. SUBSTANCE: described is method of combined preparation of 1-ethyl-2-phenylalumacyclopropane of formula I:

and 1-ethyl-2,4-diphenylalumacyclopentane of formula II:

. Method comprises reacting styrene (

) with ethyl aluminium dichloride ((EtAlCl₂)) and metallic magnesium at

Description

Предлагаемые соединения могут найти применение в качестве компонента каталитических систем в процессах олигомеризации и полимеризации олефинов и диеновых углеводородов, а также в тонком, промышленном органическом и металлоорганическом синтезе.The invention relates to methods for producing new organoaluminum compounds, specifically to a method for producing 1-ethyl-2-phenylaluminacyclopropane (1) and 1-ethyl-2,4-diphenylaluminacyclopentane (2) of the general formula:

The proposed compounds can be used as a component of catalytic systems in the processes of oligomerization and polymerization of olefins and diene hydrocarbons, as well as in fine, industrial organic and organometallic synthesis.

По известному способу в ходе реакции образуются непредельные циклические алюминий органические соединения с арильными заместителями исключительно во 2^м и 3^м - положении по отношению к атому алюминия. Известный способ не позволяет получать 1-этил-2-фенилалюмациклопропан и 1-этил-2,4-дифенилалюмациклопентан.A known method (DZHEMILEV UM et. Al., Mendeleev Commun., 1992, N 4, p.135-136) for the preparation of cyclic aluminum organic compounds, namely: 1-ethyl-cis-2,3-diphenylalumacyclopent-2-ene by interaction diphenylacetylene with triethylaluminum, taken in a molar ratio of 1: 1.1, respectively, in the presence of a two-component catalyst (3 mol.%) Cp ₂ ZrCl ₂ + i-Bu ₂ AlH in aromatic solvents at room temperature according to the scheme:

According to the known method, unsaturated cyclic aluminum organic compounds with aryl substituents exclusively in the 2 ^m and 3 ^m position with respect to the aluminum atom are formed during the reaction. The known method does not allow to obtain 1-ethyl-2-phenylalumacyclopropane and 1-ethyl-2,4-diphenylalumacyclopentane.

По известному способу в ходе реакции образуются исключительно 3,4-дибензилзамещенные алюмациклопентаны. Известный способ не позволяет получать 1-этил-2,4-дифенилалюмациклопентан и 1-этил-2-фенилалюмациклопропан. Таким образом, в литературе совершенно отсутствуют сведения по региоселективному синтезу 1-этил-2,4-дифенилалюмациклопентана и 1-этил-2-фенилалюмациклопропана.A known method (Dzhemilev U.M. et al., Synthesis and transformation of metalcycles, Izv. AN SSSR, chemical series, 1991, N 7, pp. 1607-1609) for the preparation of 1-ethyl-trans-3,4-dibenzylaluminacyclopentane by the interaction of allylbenzene with ethyl aluminum dichloride and metallic magnesium, taken in a 2: 1: 1 molar ratio, in a THF solution at room temperature in the presence of 5 mol% of a Cp ₂ ZrCl ₂ catalyst according to the scheme:

According to the known method, exclusively 3,4-dibenzyl substituted aluminacyclopentanes are formed during the reaction. The known method does not allow to obtain 1-ethyl-2,4-diphenylalumacyclopentane and 1-ethyl-2-phenylalumacyclopropane. Thus, in the literature there is absolutely no information on the regioselective synthesis of 1-ethyl-2,4-diphenylalumacyclopentane and 1-ethyl-2-phenylalumacyclopropane.

 A new method of regioselective synthesis of 1-ethyl-2,4-diphenylalumacyclopentane and 1-ethyl-2-phenylalumacyclopropane is proposed.

с этил-алюминийдихлоридом (Et-AlCl₂) и металлическим магнием (порошок), взятых в молярном соотношении

преимущественно 10:12:12, в присутствии двухкомпонентного катализатора, состоящего из тетрахлорида циркония (ZrCl₄) и диизобутилалюминийгидрида (i-Bu₂AlH) в молярном соотношении 1:(2-4), предпочтительно 1:3. ZrCl₄ берут в количестве 2-5 мол. % по отношению к стиролу, предпочтительно 4 мол.%. Реакцию проводят в атмосфере аргона при комнатной температуре (22-23^oC) и нормальном давлении. Время реакции 6-10 часов, выход целевых продуктов 61-76%. В качестве растворителя необходимо использовать тетрагидрофуран (ТГФ), в других эфирных растворителях (эфир, диоксан) выход целевых продуктов (1) и (2) значительно снижается. Соотношение 1-этил-2-фенилалюмациклопропана (1) и 1-этил-2,4-дифенилалюмациклопентана (2) составляет ~ 1:2. Реакция протекает по схеме:

Циклические алюминийорганические соединения (1) и (2) образуются только лишь с участием Et-AlCl₂ и двухкомпонентного катализатора ZrCl₄ + i-Bu₂AlH. В присутствии других соединений алюминия (например, Et₃Al, Et₂AlCl, i-Bu₃Al, i-Bu₂AlCl) или другого катализатора (например, Zr(OBu)₄ и Zr(acac)₄) целевые продукты (1) и (2) не образуются. Необходимым условием для формирования (1) и (2) является наличие в качестве исходных реагентов металлического магния (порошок) и стирола.The essence of the method is the interaction of styrene

with ethyl aluminum dichloride (Et-AlCl ₂ ) and magnesium metal (powder), taken in a molar ratio

preferably 10:12:12, in the presence of a two-component catalyst consisting of zirconium tetrachloride (ZrCl ₄ ) and diisobutylaluminium hydride (i-Bu ₂ AlH) in a molar ratio of 1: (2-4), preferably 1: 3. ZrCl ₄ take in an amount of 2-5 mol. % with respect to styrene, preferably 4 mol.%. The reaction is carried out in an argon atmosphere at room temperature (22-23 ^o C) and normal pressure. The reaction time of 6-10 hours, the yield of target products 61-76%. As a solvent, it is necessary to use tetrahydrofuran (THF), in other ether solvents (ether, dioxane), the yield of the target products (1) and (2) is significantly reduced. The ratio of 1-ethyl-2-phenylalumacyclopropane (1) and 1-ethyl-2,4-diphenylalumacyclopentane (2) is ~ 1: 2. The reaction proceeds according to the scheme:

The cyclic organoaluminum compounds (1) and (2) are formed only with the participation of Et-AlCl ₂ and the two-component catalyst ZrCl ₄ + i-Bu ₂ AlH. In the presence of other aluminum compounds (e.g., Et ₃ Al, Et ₂ AlCl, i-Bu ₃ Al, i-Bu ₂ AlCl) or another catalyst (e.g. Zr (OBu) ₄ and Zr (acac) ₄ ), the desired products (1 ) and (2) are not formed. A necessary condition for the formation of (1) and (2) is the presence of metal magnesium (powder) and styrene as initial reagents.

The reaction in the presence of a ZrCl ₄ catalyst _of more than 5 mol% with respect to styrene does not lead to a significant increase in the yield of the target products. The use of a catalyst of less than 2 mol.% In the reaction reduces the yield of 1-ethyl-2,4-diphenylalumacyclopentane and 1-ethyl-2-phenylalumacyclopropane, which is associated with a decrease in catalytically active centers in the reaction mass. The two-component ZrCl ₄ + i-Bu ₂ AlH system is more active than the ZrCl ₄ catalyst, which is associated with the formation of more active zirconium hydride complexes during the reaction. The experiments were carried out at room temperature (22-23 ^o C). At a higher temperature (for example, 50 ^o C), the content of the seal products increases, at a lower temperature (for example, 0 ^o C) the reaction rate decreases.

не приводит к значительному повышению выхода целевых продуктов. Снижение количества Et-AlCl₂ или Mg по отношению к стиролу уменьшает выход (1) и (2).The change in the ratio of the starting reagents in the direction of increasing the content of Et-AlCl ₂ or metallic magnesium (Mg) with respect to styrene

does not lead to a significant increase in the yield of target products. A decrease in the amount of Et-AlCl ₂ or Mg with respect to styrene decreases the yield of (1) and (2).

Significant differences of the proposed method:
1. The proposed method is based on the use of styrene with a system of conjugated double bonds, magnesium metal and a two-component catalyst ZrCl ₄ + i-Bu ₂ AlH, while the known method uses α-olefins with an isolated terminal double bond, a one-component catalyst Cp ₂ ZrCl ₂ and metallic magnesium (Mg).

The proposed method has the following advantages:
1. The method allows to obtain with high regioselectivity individual 1-ethyl-2,4-diphenylalumacyclopentane and 1-ethyl-2-phenylalumacyclopropane, the synthesis of which is not described in the literature.

Спектр ЯМР ¹³C ( δ, м. д.) этилбензола (3): 15.7к (С¹), 28.9т (C²), 144.2c (C³), 127.9д (C⁴, C⁸), 128.4д (C⁵, C⁷), 125.7д (C⁶).The method is illustrated by the following example.
Example. 15 ml of THF, 0.4 mmol of ZrCl ₄ , 1.2 mmol of i-Bu ₂ AlH, 10 mmol of styrene, 12 mmol of Mg and 12 mmol of Et are placed in a 50 ml glass reactor mounted on a magnetic stirrer in an argon atmosphere at a temperature of 22-23 ^° C -AlCl ₂ , stirred for 8 hours at room temperature. Individual 1-ethyl-2,4-diphenylalumacyclopentane and 1-ethyl-2-phenylalumacyclopropane are obtained. The total yield and the ratio of the target products were determined by hydrolysis products (69%). The hydrolysis of 1-ethyl-2-phenylcyclopropane (1) and 1-ethyl-2,4-diphenylaluminacyclopentane (2) produces ethylbenzene (3) and 1,3-diphenylbutane (4), respectively. During deuterolysis (1) and (2), 1,2-dideuteroethylbenzene (5) and 1,4-dideutero-1,3-diphenylbutane (6) are formed, respectively, according to the scheme:

¹³ C NMR spectrum (δ, ppm) of ethylbenzene (3): 15.7 k (C ¹ ), 28.9 t (C ² ), 144.2 c (C ³ ), 127.9 d (C ⁴ , C ⁸ ), 128.4 d (C ⁵ , C ⁷ ), 125.7 d (C ⁶ ).

¹³ C NMR spectrum (δ, ppm) of 1,3-diphenylbutane (4): 22.50к (C ¹ ), 39.49 d (C ² ), 39.96 t (C ³ ), 33.94 t (C ⁴ ), 142.47 c (C ⁵ ), 128.21 d (C ⁶ , C ¹⁰ ), 128.34 d (C ⁷ , C ⁹ ), 125.61 d (C ⁸ ), 147.24 c (C ¹¹ ), 127.09 d (C ¹² , C ¹⁶ ), 128.34d (C ¹³ , C ¹⁵ ), 125.92d (C ¹⁴ ).

22 Гц, C¹), 28.57т

22 Гц, C²), 144.23с (C³), 127.90д (C⁴, C⁸), 128.37д (C⁵, C⁷), 125.65д (C⁶). ¹³ C NMR spectrum (δ, ppm) of 1,2-dideuteroethylbenzene (5): 15.4t

22 Hz, C ¹ ), 28.57 t

22 Hz, C ² ), 144.23 s (C ³ ), 127.90 d (C ⁴ , C ⁸ ), 128.37 d (C ⁵ , C ⁷ ), 125.65 d (C ⁶ ).

19.5 Гц, C¹), 39.36д (C²), 39.83т (C³), 33,55т (

19.5 Гц, C⁵), 142.39с (C⁵), 128.21д (C⁶, C¹⁰), 128.30д (C⁷, C⁹), 125.56д (C⁸), 147.15с (C¹¹), 126.99д (C¹², C¹⁶), 128. 30д (C¹³, C¹⁵), 125.87д (C¹⁴). ¹³ C NMR spectrum (δ, ppm) of 1,4-dideutero-1,3-diphenylbutane (6): 22.14t (

19.5 Hz, C ¹ ), 39.36 d (C ² ), 39.83 t (C ³ ), 33.55 t (

19.5 Hz, C ⁵ ), 142.39 s (C ⁵ ), 128.21 d (C ⁶ , C ¹⁰ ), 128.30 d (C ⁷ , C ⁹ ), 125.56 d (C ⁸ ), 147.15 s (C ¹¹ ), 126.99 d (C ¹² , C ¹⁶ ), 128.30 d (C ¹³ , C ¹⁵ ), 125.87 d (C ¹⁴ ).

All experiments were carried out at room temperature (22-23 ^o C) in THF. In other ether solvents (ether, dioxane), the yield of the target products is significantly reduced.

 Other examples confirming the method are given in the table.

Claims (1)

The method of co-production of 1-ethyl-2-phenylalumacyclopropane and 1-ethyl-2,4-diphenylalumacyclopentane, characterized in that styrene

subjected to interaction with ethylaluminium dichloride (Et-AlCl ₂ ) and magnesium metal in a molar ratio

equal to 10: (10-14): (10-14), in the presence of a two-component catalyst consisting of zirconium tetrachloride (ZrCl ₄ ) in an amount of 2-5% with respect to styrene and diisobutylaluminum hydride (i-Bu ₂ AlH) in molar a ratio of 1: (2 - 4), and the reaction is carried out in an argon atmosphere, in tetrahydrofuran medium under normal conditions for 6 to 10 hours

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