RU2156773C2 - Method of preparing 1,2-bis(dialkylaluma)-1- phenyl(alkyl)ethanes - Google Patents

Abstract

FIELD: chemical industry, more particularly organometallic and fine organic synthesis. SUBSTANCE: described is method of preparing new 1,2- bis(dialkylaluma)-1-phenyl(alkyl)ethanes of formula I:

wherein R is Ph, n-C₆H₁₃: R¹ is Et, i-B4 which are useful as catalyst complex components in processes of polymerization and oligomerization of olefin and diene hydrocarbons, method comprises reacting dialkylaluminium chloride R $\genfrac{}{}{0ex}{}{\text{1}}{\text{2}}$ AlCl with alpha olefin

and metallic magnesium at

ratio of 10:(20-30):(10-14), respectively in the presence of titanocene dichloride ((Cp₂TiCl₂)) catalyst in argon atmosphere in tetrahydrofuran under normal conditions and agitation for 6-10 hours. EFFECT: high regioselectivity of the title compounds. 11 ex, 1 tbl

Description

где R=Ph, н-C₆H₁₃;
R'=Et, i-Bu
Полученные соединения могут найти применение в качестве компонентов каталитических комплексов в процессах полимеризации и олигомеризации олефиновых и диеновых углеводородов, а также в металлорганическом и тонком органическом синтезе.The invention relates to methods for producing new organoaluminum compounds, specifically to 1,2-bis (dialkylalum) -1-phenyl (alkyl) ethanes of the general formula (1):

where R = Ph, n-C ₆ H ₁₃ ;
R '= Et, i-Bu
The obtained compounds can be used as components of catalytic complexes in the polymerization and oligomerization of olefin and diene hydrocarbons, as well as in organometallic and fine organic synthesis.

или изопрена

с помощью диизобутилалюминийгидрида (i-Bu₂AlH) в автоклаве при температуре 80 - 85^oC за 13 часов по схеме:

Недостатки известного способа:
1. Гидроалюминирование сопряженных 1,3-диенов сопровождается образованием продуктов уплотнения, кроме того конверсия 1,3-диенов не превышает 50%.The known method / Zakharkin L.I., Savina L.A. Izv. USSR Academy of Sciences, Ser. Chem., 1967, p. 78 - 84 / for the preparation of dialyuminium compounds, in particular 1,4-bis (diisobutylalum) butane and 1,4-bis (diisobutylalum) -2-methylbutane, by hydroalumination of butadiene

or isoprene

using diisobutylaluminum hydride (i-Bu ₂ AlH) in an autoclave at a temperature of 80 - 85 ^o C for 13 hours according to the scheme:

The disadvantages of this method:
1. Hydroalumination of conjugated 1,3-dienes is accompanied by the formation of compaction products, in addition, the conversion of 1,3-dienes does not exceed 50%.

 2. The known method does not allow to obtain 1,2-bis (dialkylalum) -1-phenyl (alkyl) ethanes.

Известный способ не позволяет получать 1,2-бис(диалкилалюма)-1-фенил(алкил)-этаны.The known method / G. Dozzi, S. Cucinella, A. Mazzei. J. Organometal. Chem. 164 (1979), p. 1-10 / obtaining dialyuminium compounds, in particular 1,4-bis (dialum) -2-methylbutane, by hydroalumination of isoprene with amine aluminum hydride (AlH ₃ • N (CH ₃ ) ₃ ) in the presence of a titanocene dichloride catalyst (Cp ₂ TiCl ₂ ) at a temperature of 80 ^o C for 1 hour. Hydrolysis of the resulting dialuminium compound leads to isopentane in 93% yield. The reaction proceeds according to the scheme:

The known method does not allow to obtain 1,2-bis (dialkylalum) -1-phenyl (alkyl) ethanes.

 Thus, in the literature there is absolutely no information on the synthesis of 1,2-bis (dialkylalum) -1-phenyl (alkyl) ethanes.

 A method for the regioselective synthesis of 1,2-bis (dialkylalum) -1-phenyl (alkyl) ethanes is proposed.

= (20-30):10:(10-14), предпочтительно 25:10:12, в присутствии катализатора титаноцендихлорида (Cp₂TiCl₂) в количестве 2-5 мол.% по отношению к α - олефину, предпочтительно 4 мол.%, в атмосфере аргона при комнатной температуре (22-24^oC) и нормальном давлении в ТГФ при перемешивании в течение 6-10 часов. Получают 1,2-бис-(диалкилалюма)-1-фенил(алкил)-этаны с выходами 74-89%. Реакция протекает по схеме:

Проведение указанной реакции в присутствии катализатора Cp₂TiCl₂ больше 5 мол. % не приводит к существенному увеличению выхода целевых продуктов. Использование катализатора Cp₂TiCl₂ менее 2 мол.% по отношению к дизамещенному ацетилену снижает выход 1,2-диалюминиевых соединений (1), что связано с уменьшением реакционных центров. Опыты проводили при комнатной температуре (22-24^oC). При более высокой температуре, например 60^oC, увеличивается содержание продуктов уплотнения, при меньшей температуре, например 0^oC, снижается скорость реакции.The essence of the method consists in the interaction of dialkylaluminium chlorides (Et ₂ AlCl, i-Bu ₂ AlCl) with α-olefins (styrene, 1-octene) and magnesium metal (powder), taken in a molar ratio

= (20-30): 10: (10-14), preferably 25:10:12, in the presence of a titanocene dichloride catalyst (Cp ₂ TiCl ₂ ) in an amount of 2-5 mol% with respect to α-olefin, preferably 4 mol %, in an argon atmosphere at room temperature (22-24 ^o C) and normal pressure in THF with stirring for 6-10 hours. 1,2-bis- (dialkylalum) -1-phenyl (alkyl) ethanes are obtained in yields of 74-89%. The reaction proceeds according to the scheme:

The specified reaction in the presence of a catalyst Cp ₂ TiCl ₂ more than 5 mol. % does not lead to a significant increase in the yield of target products. The use of the catalyst Cp ₂ TiCl ₂ less than 2 mol.% In relation to disubstituted acetylene reduces the yield of 1,2-diallyuminium compounds (1), which is associated with a decrease in reaction centers. The experiments were carried out at room temperature (22-24 ^o C). At a higher temperature, for example 60 ^o C, the content of the products of compaction increases, at a lower temperature, for example 0 ^o C, the reaction rate decreases.

Without the catalyst Cp ₂ TiCl _{2 the} reaction does not proceed. It is not possible to obtain 1,2-diallyuminium compounds without Et ₂ AlCl and i-Bu ₂ AlCl or replacing them with other organoaluminum compounds, for example AlEt ₃ , i-Bu ₃ Al, EtAlCl ₂ , i-Bu ₂ AlH. It is not possible to obtain 1,2-diallyuminium compounds when replacing α-olefins with other unsaturated compounds, for example acetylene or 1,3-diene hydrocarbons.

в то время как в предлагаемом реакция протекает в присутствии металлического Mg, α - олефинов

а в качестве алюминийорганических соединений используются Et₂AlCl или i-Bu₂AlCl.The differences of the proposed method from the known:
1. In the known method, the amine complex of aluminum hydride (AlH ₃ • N (CH ₃ ) ₃ ) and isoprene are used

while in the proposed reaction proceeds in the presence of metallic Mg, α - olefins

and organoaluminum compounds are Et ₂ AlCl or i-Bu ₂ AlCl.

 The proposed method, unlike the known ones, allows one to obtain individual 1,2-bis (dialkylalum) -1-phenyl (alkyl) ethanes, the synthesis of which is not described in the literature.

 The method is illustrated by examples.

Спектр ЯМР ¹³C ( δ, м.д.) этилбензола (2): 15,76к (C¹), 28,93т (C²), 144,21с (C³), 127,94д (C⁴, C⁸), 128,41д (C⁵, C⁷), 125,69д (C⁶). M⁺ 106.Example 1. In a 50 ml glass reactor mounted on a magnetic stirrer, in an argon atmosphere was placed 10 mmol of styrene in 12 ml of dry THF, 12 mmol of magnesium (powder), 0.4 mmol of Cp ₂ TiCl and at a temperature of ≈0 ^o C 25 mmol Et ₂ AlCl was stirred for 8 hours at room temperature (22-23 ^o C). Obtain 1,2-bis (diethylalum) -1-phenylethane with a yield of 83%. The yield of the target product was determined by the hydrolysis product. During the hydrolysis of 1,2-bis (diethylalum) -1-phenyl-ethane, ethylbenzene is formed (2), and during the deuterolysis, respectively, 1,2-dideuteroethylbenzene (3) according to the scheme:

¹³ C NMR spectrum (δ, ppm) of ethylbenzene (2): 15.76 k (C ¹ ), 28.93 t (C ² ), 144.21 s (C ³ ), 127.94 d (C ⁴ , C ⁸ ), 128.41d (C ⁵ , C ⁷ ), 125.69d (C ⁶ ). M ⁺ 106.

¹³ C NMR spectrum (δ, ppm) of 1,2-dideuteroethylbenzene (3): 15.42 t (J _13C-D = 22 Hz, C ¹ ), 28.57 t (J _13C-D = 22 Hz, C ² ), 144.20 s (C ³ ), 127.94 d (C ⁴ , C ⁸ ), 128.39 d (C ⁵ , C ⁷ ), 125.68 d (C ⁶ ). M ⁺ 108.

 Other examples confirming this method are shown in the table.

All experiments were carried out at room temperature (22-23 ^o C) in THF. In other solvents (ether, benzene), the yield of the target product sharply decreased.

Claims (1)

The method of producing 1,2-bis (dialkylalum) -1-phenyl (alkyl) ethanes of the general formula I

where R is Ph, n is C ₆ H ₁₃ ;
R '- Et, i - Bu,
characterized in that the α-olefin of the General formula

where R is described above
reacted with dialkylaluminium chloride of the general formula
R ' ₂ AlCl,
where R is described above
and metallic magnesium in a molar ratio

equal to 10: (20 - 30): (10 - 14), respectively, in the presence of a catalyst of titanocene dichloride (Cp ₂ TiCl ₂ ) in an amount of 2 to 5 mol% with respect to the α-olefin and the reaction is carried out in an argon atmosphere under normal conditions in medium tetrahydrofuran with stirring for 6 to 10 hours

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