RU2153500C1 - Method of preparing diphenyl di[(1-ethyl-1-alumo- cyclopent-3-yl)methyl]silane - Google Patents

Abstract

FIELD: chemical industry. SUBSTANCE: described is new method of preparing new compound such as diphenyl di[(1-ethyl-1-alumocyclopent-3- yl)methyl] silane by reacting diphenyldiallyl silane with triethyl aluminium in the presence of zirconadene dichloride catalyst in argon atmosphere in aliphatic solvent under normal conditions for 6-10 hours. EFFECT: more efficient preparation method. 1 tbl

Description

Полученное соединение может найти применение в качестве компоненты каталитических комплексов в процессах полимеризации и олигомеризации олефиновых и диеновых углеводородов, а также в металлоорганическом и тонком органическом синтезе, в частности в региоселективном синтезе 2-кремнийсодержащих 1,4- бутандиолов.The invention relates to methods for producing new silicon-containing organoaluminum compounds, specifically to a method for producing diphenyldi [(1-ethyl-1-aluminocyclopent-3-yl) methyl] silane of the general formula (1):

The obtained compound can find application as a component of catalytic complexes in the polymerization and oligomerization of olefin and diene hydrocarbons, as well as in organometallic and fine organic synthesis, in particular in regioselective synthesis of 2-silicon-containing 1,4-butanediols.

The known method [E. Negichi, F. Luo, CLRand. Tetrahedron Lett., 23, N 1, 27-30, 1982] for the preparation of silicon-containing organoaluminum compounds by the interaction of trimethylpropargyl silane with trimethylaluminum (Me ₃ Al) in the presence of a Cp ₂ ZrCl ₂ catalyst at room temperature for 2 h according to Scheme 1 (Scheme 1, see end of description).

 The known method does not allow to obtain silicon-containing aluminocyclopentanes (1).

The known method [JA Miller, E. Negichi. Israel J. Chem. 1984, 24, 76] for the preparation of A1- and Si-containing methylenecyclopentanes by the interaction of silicon-containing enins with i-Bu ₃ Al in the presence of a Cp ₂ ZrCl ₂ catalyst according to Scheme 2 (see Scheme 2 at the end of the description).

 According to the known method, exclusively regioisomeric methylene cyclopentanes containing Si and A1 atoms in the double bond are formed during the reaction. The known method does not allow to obtain silicon-containing aluminocyclopentanes (1).

 Thus, in the literature there is no information on the regioselective synthesis of diphenyldi [(1-ethyl-1-aluminocyclopent-3-yl) methyl] silane (1).

 A new method for the regioselective synthesis of diphenyldi [(1-ethyl-1-aluminocyclopent-3-yl) methyl] silane (1) is proposed.

с триэтилалюминием (AlEt₃), взятых в мольном соотношении;

= 10:(20 - 30), преимущественно 10:25, в присутствии катализатора цирконацендихлорида (Cp₂ZrCl₂) в количестве 4-6 мол% по отношению к дифенилдиаллилсилану, предпочтительно 5 мол%. Реакцию проводят в атмосфере аргона при комнатной температуре (21-22^oC) и нормальном давлении. Время реакции 6-10 часов. Выход целевого продукта 82-94%. Необходимо использовать алифатические растворители (гексан, гептан). В эфирных (ТГФ, диоксан, Et₂O) или галогенсодержащих (хлористый метилен, дихлорэтан) растворителях реакция не идет. Реакция протекает по схеме 3 (cхему 3 см. в конце описания).The essence of the method consists in the interaction of diphenyldiallylsilane

with triethylaluminium (AlEt ₃ ), taken in a molar ratio;

= 10: (20-30), preferably 10:25, in the presence of a catalyst of zirconacene dichloride (Cp ₂ ZrCl ₂ ) in an amount of 4-6 mol% with respect to diphenyldiallyl silane, preferably 5 mol%. The reaction is carried out in an argon atmosphere at room temperature (21-22 ^o C) and normal pressure. The reaction time is 6-10 hours. The yield of the target product 82-94%. Aliphatic solvents (hexane, heptane) must be used. In ether (THF, dioxane, Et ₂ O) or halogen-containing (methylene chloride, dichloroethane) solvents, the reaction does not proceed. The reaction proceeds according to scheme 3 (scheme 3 see at the end of the description).

, принимающего участие в формировании силилзамещенного алюмоциклопентанового фрагмента.The reaction is accompanied by the release of ethane. The target product (1) is formed only with the participation of AlEt ₃ and the catalyst Cp ₂ ZrCl ₂ . In the presence of other aluminum compounds (e.g. Et ₂ AlCl ₂ , i-Bu ₃ Al, i-Bu ₂ AlCl, i-Bu ₂ AlH) or other transition metals (e.g. Zr (acac) ₄ , Fe (acac) ₃ , FeCl ₃ , NiCl ₂ , PdCl ₂ , TiCl ₄ ) the target product (1) is not formed. A prerequisite for obtaining the target product (1) is the presence of diphenyldiallylsilane as the starting compound

participating in the formation of silyl substituted aluminocyclopentane fragment.

The reaction in the presence of a catalyst Cp ₂ ZrCl ₂ more than 6 mol% with respect to diphenyldiallyl silane does not significantly increase the yield of the target product (1). The use of Cp ₂ ZrCl ₂ in the reaction of the catalyst less than 4 mol% reduces the yield of diphenyldi [(1-ethyl-1-algomocycclopent-3-yl) methyl] silane (1), which is associated with a decrease in catalytically active centers in the reaction mass. The experiments were carried out at room temperature (21-22 ^o C). At a higher temperature (for example, 60 ^o C) the content of the seal products increases slightly, at a lower temperature (for example, 0 ^o C) the reaction rate decreases.

уменьшает выход (1).The change in the ratio of the starting reagents in the direction of increasing the content of AlEt ₃ relative to diphenyldiallylsilane does not significantly increase the yield of the target product (1). The decrease in the amount of AlEt ₃ relative to

reduces output (1).

Significant differences of the proposed method:
The proposed method is based on the use of diphenyldiallylsilane and AlEt ₃ as starting reagents, while the known method uses silicon-containing enin and i-Bu ₃ Al.

 The proposed method allows to obtain with high regioselectivity individual diphenyldi [(1-ethyl-1-alumocyclopent-3-yl) methyl] silane (1), the synthesis of which is not described in the literature.

The method is illustrated by the following examples:
EXAMPLE 1. In a 50 ml glass reactor mounted on a magnetic stirrer in an argon atmosphere at a temperature of ~ 0 ^° C, 10 mmol of diphenyldiallylsilane in 2 ml of hexane, 0.5 mmol of Cp ₂ ZrCl ₂ are added, 25 mmol of AlEt _{3 is} added slowly, stirred for 8 hours at room temperature (21-22 ^o C).

 Get individual diphenyldi [(1-ethyl-1-aluminocyclopent-3-yl) methyl] silane (1). The yield of the target product was determined by the hydrolysis product (88%). During hydrolysis (1), diphenyldi (2-methylbutyl) silane (2) is formed (see Scheme 4 at the end of the description).

¹³ C NMR spectrum of diphenyldi (2-methylbutyl) silane (2) (δ ppm): 128.93 d (C ¹ ), 127.69 d (C ² ), 135.11 d (C ³ ), 134.33 s (C ⁴ ), 22.61 t (C ⁵ ), 33.34 d (C ⁶ ), 30.93 t (C ⁷ ), 11.94 k (C ⁸ ), 21.37 k (C ⁹ ).

 Other examples confirming the method are given in table 1.

All experiments were carried out at room temperature 21-22 ^o C in hexane. In ether or halogen-containing solvents, the reaction does not proceed.

Claims (1)

The method of obtaining diphenyldi [(1-ethyl-1-aluminocyclopent-3-yl) methyl] silane of the General formula

characterized in that diphenyldiallylsilane interacts with triethylaluminium in a molar ratio of 10: (20-30), respectively, in the presence of a catalyst of zirconacenedichloride in an amount of 4-6 mol% with respect to diphenyldiallyl silane in an argon atmosphere in an aliphatic solvent under normal conditions for 6-10 h

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