RU2191192C1 - Method of synthesis of substituted 1-ethylalumo-cyclopentanes - Google Patents

Abstract

FIELD: organometallic compounds, chemical technology. SUBSTANCE: invention describes a method of synthesis of substituted 1- ethylalumocyclopentanes of the general formula (1)

where R means n-C₆H₁₃, n-C₈H₁₇, Ph characterized that substituted allenes of the general formula R-=•= where R has a value indicated above is subjected for an interaction with triethylaluminium Et₃Al in the mole ratio R-=•= : Et₃Al = 10 : (10-14), respectively, in the presence of zirconacene dichloride (Cp₂ZrCl₂) as a catalyst taken in the amount 2-6 mole % with respect to a substituted allene. The reaction is carried out in methylene chloride medium, in argon atmosphere at the room temperature (~20 C) and under normal pressure for 8-12 h. New compounds can be used as a component of catalytic systems in processes of oligo- and polymerization of olefin, diene and acetylene hydrocarbons and in the fine organic and organometallic synthesis also. EFFECT: improved method of synthesis. 1 tbl, 9 ex

Description

,
где R=н-С₆Н₁₃, H-C₈H₁₇, Ph
Предлагаемые соединения могут найти применение в качестве компоненты каталитических систем в процессах олиго- и полимеризации олефиновых, диеновых и ацетиленовых углеводородов, а также в тонком органическом и металлоорганическом синтезе.The present invention relates to methods for producing new organoaluminum compounds (AOC), specifically to a method for producing 1-ethylaluminacyclopentanes of the general formula (1)

,
where R = nC ₆ H ₁₃ , HC ₈ H ₁₇ , Ph
The proposed compounds can be used as a component of catalytic systems in the processes of oligo- and polymerization of olefin, diene and acetylene hydrocarbons, as well as in fine organic and organometallic synthesis.

R=Me, Et, n-Bu.A known method ([1], RF Patent 2157812, class C 07 F 7/2, 5/6) for the preparation of substituted five-membered cyclic AOC, namely 1-ethyl-3 (trialkylsilyl) aluminacyclopentanes (2) by reacting trialkyl vinyl silanes with triethyl aluminum (AlEt ₃ ) in the presence of a catalyst Cp ₂ ZrCl ₂ taken in a molar ratio of trialkyl vinyl silane: AlEt ₃ : Cp ₂ ZrCl ₂ = 10: 15: 0.5, at a temperature of 21-22 ^o C for 6-10 hours according to the scheme

R = Me, Et, n-Bu.

 The known method does not allow to obtain unsaturated aluminacyclopentanes (1).

Известный способ не позволяет получать замещенные 1-этилалюмациклопентаны (1).The known method ([2], Dzhemilev UM, Ibragimov AG, Zolotarev AP Synthesis of 1-Ethyl-cis-2,3-dialkyl (aryl) aluminacyclopent-2-enes. A Novel Class of Five - membered Organoaluminum Compounds. Mendeleev Commun. , 1992, 4, p.135) for the preparation of unsaturated five-membered cyclic AOS, namely: 1-ethyl-2,3-dialkylalumacyclopent-2-enes (3) by the interaction of dialkylacetylenes with triethylaluminium taken in a molar ratio of 1: 2.5, respectively the presence of 3-5 mol. % Cp ₂ ZrCl ₂ at a temperature of 23-25 ^o C for 10-12 hours according to the scheme

The known method does not allow to obtain substituted 1-ethylaluminacyclopentanes (1).

 Thus, in the literature there is no information on the selective synthesis of substituted 1-ethylaluminacyclopentanes (1).

 A new method for the synthesis of substituted 1-ethylaluminacyclopentanes (1) is proposed.

The essence of the method consists in the interaction of substituted allens of the general formula R- = • =, where R = n-C ₆ H ₁₃ , n-C ₈ H ₁₇ , Ph, with triethylaluminum (Et ₃ Al), taken in a molar ratio of R- = • =: Et ₃ Al = 10: (10-14), preferably 10:12, in the presence of a catalyst of zirconacene dichloride (Cp ₂ ZrCl ₂ ) in an amount of 2-6 mol. % with respect to the 1-substituted allene, preferably 4 mol%, in an argon atmosphere at room temperature (~ 20 ^{° C.} ) and normal pressure in methylene chloride (CH ₂ Cl ₂ ) as a solvent. The reaction time is 8-12 hours, preferably 10 hours. The total yield of substituted 1-ethylaluminacyclopentanes (1) is 82-96%.

R=н-С₆Н₁₃; н-С₈Н₁₇, Рh.The reaction proceeds according to the scheme.

R = n-C ₆ H ₁₃ ; nC ₈ H ₁₇ , Ph.

Substituted 1-ethylaluminacyclopentanes (1) are formed only with the participation of Et ₃ Al and the zirconium catalyst Cp ₂ ZrCl ₂ . In the presence of other aluminum compounds (e.g., Bu ₂ ⁱ AlCl, Bu ₃ ⁱ Al, Bu ₂ ⁱ AlH, EtAlCl ₂ , Et ₂ AlCl) or another catalyst (e.g. Zr (acac) ₄ , ZrCl ₄ , Cp ₂ TiCl ₂ , Pd (acac) ₂ , Ni (acac) ₂ , NiCl ₂ , Fe (acac) ₂ ) the target products (1) are not formed.

Carrying out the specified reaction in the presence of a zirconium catalyst Cp ₂ ZrCl ₂ more than 6 mol. % does not lead to a significant increase in the yield of target products (1). The use of catalyst less than 2 mol. % reduces the yield of AOS (1), which is possibly associated with a decrease in catalytically active centers in the reaction mass. The reaction was carried out at a temperature of ~ 20 ^o C. At a higher temperature (for example, ~ 40 ^o C) there is no significant increase in the yield of the target products, and at a lower temperature (for example, 0 ^o C) the reaction rate decreases.

A change in the ratio of the starting reagents in the direction of increasing the Et ₃ Al content with respect to the starting 1-substituted allene does not lead to a significant increase in the yield of the target products (1).

 Reactions were carried out using methylene chloride as a solvent. In other solvents (e.g., aliphatic or aromatic), the regioselectivity of the reaction decreases and, along with substituted 1-ethylaluminacyclopentanes (1), the formation of significant amounts of 1-ethyl-2-methylene-3-alkylaluminacyclonentanes is observed.

Significant differences of the proposed method:
In the proposed method, substituted allens are used as starting unsaturated compounds, which determine the formation of substituted 1-ethylaluminacyclopentanes (1). In the known method, disubstituted acetylenes which contribute to the formation of 1-ethyl-2,3-dialkylaluminacyclopent-2-enes are used as starting unsaturated compounds (3).

The proposed method has the following advantages:
1. The method allows to obtain with high selectivity substituted 1-ethylaluminacyclopentanes (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, 5 ml of methylene chloride (CH ₂ Cl ₂ ), 10 mmol of 1,2-nonadiene, 0.4 mmol of Cp ₂ ZrCl ₂ at a temperature of ~ 0 are placed in an argon atmosphere ^o With 12 mmol Et ₃ Al, stirred for 10 hours at room temperature (~ 20 ^o C). 1-Ethyl-2-heptylidenealuminacyclopentane (1) is obtained in 88% yield.

Спектр ЯМР ¹³С (δ, м.д.) 1-этил-2-гептилиденалюмациклопентана (1): 18,10 уш. с. (С¹), 33,41 т (С²), 34,88 т (С³), 170,40 уш.с. (С⁴), 146,53 д (С⁵), 25,45 т (С⁶), 28,77 т (С⁷), 29,61 т (С⁸), 32,18 т (С⁹), 23,11 т (С¹⁰), 14,33 к (С¹¹), 0,81 т (С¹²), 8,26 к (С¹³).

¹³ C NMR spectrum (δ, ppm) of 1-ethyl-2-heptylidenealuminacyclopentane (1): 18.10 br. from. (C ¹ ), 33.41 t (C ² ), 34.88 t (C ³ ), 170.40 br.s. (C ⁴ ), 146.53 d (C ⁵ ), 25.45 t (C ⁶ ), 28.77 t (C ⁷ ), 29.61 t (C ⁸ ), 32.18 t (C ⁹ ), 23.11 t (C ¹⁰ ), 14.33 k (C ¹¹ ), 0.81 t (C ¹² ), 8.26 k (C ¹³ ).

 Other examples confirming the method are given in the table.

The reaction was carried out at room temperature (-20 ^o C) in methylene chloride.

Claims (1)

The method of obtaining substituted 1-ethylaluminacyclopentanes of General formula (1)

where R = nC ₆ H ₁₃ ; nC ₈ H ₁₇ ; Ph
characterized in that the substituted allens of the general formula R- = • =, where R, as defined above, is reacted with Et ₃ Al triethylaluminum in a molar ratio R- = • =: Et ₃ Al = 10: (10-14), respectively, in the presence of a catalyst of zirconacenedichloride (Ср ₂ ZrCl ₂ ) in an amount of 2-6 mol% with respect to the substituted allene and the reaction is carried out in a medium of methylene chloride in an argon atmosphere at room temperature of 20 ^o C and normal pressure for 8-12 hours

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