RU2163907C2 - Method of preparing 1-(dialkylamino)-2- (trialkylsilyl)alumacyclopropanes - Google Patents

Abstract

FIELD: catalytic complex components, organometal and fine organic synthesis. SUBSTANCE: method comprises reacting trialkylvinyl silanes with (dialkylamino)aluminium dichlorides and metallic magnesium in the presence catalyst, in argon atmosphere, under normal conditions in tetrahydrofuran solvent for 8-12 hours. Yield of the desired products is 50-68 %. EFFECT: more efficient preparation method. 12 ex, 1 tbl

Description

где R=Et, Bu и; R¹=Et, Amⁱ
Полученные соединения могут найти применение в качестве компонентов каталитических комплексов в процессах полимеризации и олигомеризации олефиновых и диеновых углеводородов, а также в металлоорганическом и тонком органическом синтезе, в частности в региоселективном синтезе кремнийзамещенных 1,2-этандиолов.The invention relates to methods for producing new silicon-containing organoaluminum compounds, in particular, to a method for producing 1- (dialkylamino) -2- (trialkylsilyl) aluminacyclopropanes of the general formula (1)

where R = Et, Bu and; R ¹ = Et, Am ⁱ
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, in particular in regioselective synthesis of silicon-substituted 1,2-ethanediols.

Известный способ не позволяет получать кремнийсодержащие алюмациклопропаны (1).The known method [E. Negichi, F. Luo, CLRand. Tetrahedron Lett., 23 N 1, 1982, pp. 27-30) obtaining silicon-containing organoaluminum compounds by the interaction of trimethylpropargylsilane with trimethylaluminum (Me ₃ Al) in the presence of a catalyst Cp ₂ ZrCl ₂ at room temperature for 2 hours according to the scheme

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

По известному способу в ходе реакции образуются исключительно региоизомерные метиленциклопентаны, содержащие атомы Si и Al при двойной связи. Известный способ не позволяет получать кремнийсодержащие алюмациклопропаны (1).The known method [JA Miller, E. Negichi. Israel J. Chem. 1984, 24, 76] obtaining Al - and Si-containing methylene cyclopentanes by the interaction of silicon-containing enins with Bu ₃ ⁱ Al in the presence of a Cp ₂ ZrCl ₂ catalyst according to the scheme:

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

 Thus, in the literature there is no information on the regioselective synthesis of 1- (dialkylamino) -2- (trialkylsilyl) aluminacyclopropanes (1).

 A method for the regioselective synthesis of 1- (trialkylamino) -2- (trialkylsilyl) aluminacyclopropanes (1) is proposed.

где R¹= Et, Amⁱ, с (диалкиламино)алюминийдихлоридами (R₂N-AlCl₂), где R-Et, Buⁿ, и металлическим магнием (порошок), взятых в мольном соотношении

преимущественно 10:14:12, в присутствии катализатора титаноцендихлорида (Cp₂ TiCl₂) в количестве 3-6 мол. % по отношению к триалкилвинилсилану, предпочтительно, 5 мол.%. Реакцию проводят в атмосфере аргона при комнатной температуре (21-22^oC) и нормальном давлении. Время реакции 8-12 часов, выход целевых продуктов 50-68%. В качестве растворителя необходимо использовать тетрагидрофуран (ТГФ). В алифатических (гексан, гептан), ароматических (бензол, толуол), галогенсодержащих (хлористый метилен, дихлорэтан) растворителях реакция не идет. Реакция протекает по схеме

R=Et, Buⁿ; R¹=Et, Amⁱ
Целевые продукты (1) образуются только лишь с участием (диалкиламино) алюминийдихлоридов (R₂N-AlCl₂), магниевого порошка (акцептора ионов хлора) и катализатора Cp₂TiCl₂. В присутствии других соединений алюминия (например, Et₂AlCl, Et₃Al, Et(Et₂N)AlCl, i-Bu₃Al, i-Bu₂AlH,) или соединений других переходных металлов (например, TiCl₄, Zr(acac)₄, Fe(acac)₃, FeCl₃, NiCl₂, PdCl₂, Cp₂ZrCl₂) целевые продукты (1) не образуются. Необходимым условием для получения целевых продуктов (1) является наличие в качестве исходных соединений триалкилвинилсиланов общей формулы

принимающим участие в формировании силилзамещенных алюмациклопропановых фрагментов.The essence of the method consists in the interaction of trialkylvinylsilanes of the form

where R ¹ = Et, Am ⁱ , with (dialkylamino) aluminum dichlorides (R ₂ N-AlCl ₂ ), where R-Et, Bu ⁿ , and magnesium metal (powder), taken in a molar ratio

mainly 10:14:12, in the presence of a titanocene dichloride catalyst (Cp ₂ TiCl ₂ ) in an amount of 3-6 mol. % with respect to trialkyl vinyl 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 8-12 hours, the yield of the target products is 50-68%. As a solvent, tetrahydrofuran (THF) must be used. In aliphatic (hexane, heptane), aromatic (benzene, toluene), halogen-containing (methylene chloride, dichloroethane) reactions do not proceed. The reaction proceeds according to the scheme.

R = Et, Bu ⁿ ; R ¹ = Et, Am ⁱ
The target products (1) are formed only with the participation of (dialkylamino) aluminum dichlorides (R ₂ N-AlCl ₂ ), magnesium powder (chlorine ion acceptor) and Cp ₂ TiCl ₂ catalyst. In the presence of other aluminum compounds (e.g., Et ₂ AlCl, Et ₃ Al, Et (Et ₂ N) AlCl, i-Bu ₃ Al, i-Bu ₂ AlH,) or compounds of other transition metals (e.g. TiCl ₄ , Zr ( acac) ₄ , Fe (acac) ₃ , FeCl ₃ , NiCl ₂ , PdCl ₂ , Cp ₂ ZrCl ₂ ) the target products (1) are not formed. A prerequisite for obtaining the target products (1) is the presence of starting compounds of trialkyl vinyl silanes of the general formula

involved in the formation of silyl substituted aluminacyclopropane fragments.

Bringing the reaction in the presence of a Cp ₂ TiCl ₂ catalyst to more than 6 mol% with respect to trialkyl vinyl silane does not significantly increase the yield of the target product (1). The use of Cp ₂ TiCl ₂ in the reaction of a catalyst _of less than 3 mol% reduces the yield of 1- (dialkylamino) -2- (trialkylsilyl) aluminacyclopropanes (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).A change in the ratio of the starting reagents in the direction of increasing the content of R ₂ N-AlCl ₂ or magnesium relative to trialkyl vinyl silane does not significantly increase the yield of the target products (1). The decrease in the amount of R ₂ N-AlCl ₂ or magnesium in relation to

reduces output (1).

(диалкиламино)алюминийдихлоридов (R₂N-AlCl₂) и магния (акцептора ионов хлора) в качестве исходных реагентов и катализатора Cp₂TiCl₂, в то время как в известном способе используются кремнийсодержащий енин, Bu₃ ⁱAl и катализатор Cp₂ZrCl₂.Significant differences of the proposed method
The proposed method is based on the use of trialkylvinylsilanes

(dialkylamino) aluminum dichlorides (R ₂ N-AlCl ₂ ) and magnesium (acceptor of chlorine ions) as the starting reagents and catalyst Cp ₂ TiCl ₂ , while the known method uses silicon-containing enin, Bu ₃ ⁱ Al and the catalyst Cp ₂ ZrCl ₂ .

 The proposed method allows to obtain with high regioselectivity individual 1- (dialkylamino) -2- (trialkylsilyl) aluminacyclopropanes (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 triethyl vinyl silane in 10 ml of THF, 12 mmol of magnesium powder, 0.5 mmol of titanocene dichloride (Cp ₂ TiCl ₂ ) are added 14 mmol Et ₂ N-AlCl ₂ in a solution of THF, stirred for 10 hours at room temperature (21-22 ^o C). Individual 1- (diethylamino) -2- (triethylsilyl) aluminacyclopropane is obtained. The yield of the target product was determined by the product of deuterolysis (62%). During deuterolysis (1), 1,2-dideuteroethyl (triethyl) silane is formed (2).

Спектр ЯМР ¹³C 1,2-дидейтероэтил(триэтил)силана (2) ( δ, м.д.): 7,12 т (J_C-D=19,2 Гц) (C¹), 2,81 т (J_C-D=19,2 Гц) (C²), 3,17 т (C³), 7,41 к (C⁴).

¹³ C NMR spectrum of 1,2-diddeteroethyl (triethyl) silane (2) (δ, ppm): 7.12 t (J _CD = 19.2 Hz) (C ¹ ), 2.81 t (J _CD = 19.2 Hz) (C ² ), 3.17 t (C ³ ), 7.41 k (C ⁴ ).

 Other examples confirming the method are given in the table.

All experiments were carried out at room temperature 21-22 ^o C in HF. In aliphatic, aromatic or halogenated solvents, the reaction does not proceed.

Claims (1)

The method of obtaining 1- (dialkylamino) -2- (trialkylsilyl) aluminacyclopropanes of the General formula

where R = Et, Bu ⁿ ;
R '= Et, Am ⁱ ,
characterized in that the trialkyl vinyl silanes of the general formula

where R 'is described above, is subjected to interaction with (dialkylamino) aluminum dichloride (R ₂ N - AlCl ₂ ), where R is described above, and metal magnesium, taken in a molar ratio

equal to 10: 10 - 18: 10 - 14, respectively, in the presence of a titanocene dichloride catalyst (Cp ₂ TiCl ₂ ) taken in an amount of 3-6 mol% with respect to trialkyl vinyl silane, and the reaction is carried out in an argon atmosphere in tetrahydrofuran medium under normal conditions in during 8 - 12 hours

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