RU2183613C1 - Method of synthesis of (z)-1,2-alkyl-1,2-diethyl-ethylenes - Google Patents

Abstract

FIELD: organic chemistry, chemical technology. SUBSTANCE: invention relates to a method of synthesis of (Z)- 1,2-dialkylethylethylenes of the general formula (I)

where R is n-C₃H₇, n-C₄H₉. The proposed method involves interaction of dialkyl-substituted acetylenes of the formula R-C≡C-R with triethylaluminium (Et₃Al) in the presence of zirconacene dichloride (Cp₂ZrCl₂) as a catalyst in their mole ratio = 10:(10-20):(0.1-0.5), respectively. Interaction is carried out under normal conditions in hexane medium at stirring for 8 h. Then to reaction mass at 0 C ethyltosylate (EtTs) is added taken in the mole ratio RC≡CR : EtTs = 10:(40-60) and reaction mass is stirred for 16-20 h at the room temperature followed by hydrolysis of reaction mass with hydrochloric acid solution. Indicated hydrocarbons can be used as monomers in processes of oligomerization, polymerization and as intermediate products in paint and varnish industry. EFFECT: enhanced of compounds of formula (I) from disubstituted acetylenes, high regio- and stereoselectivity. 1 tbl

Description

где R=n-C₃H₇,n-C₄H₉
Ненасыщенные углеводороды и их производные могут найти применение в качестве исходных мономеров в процессах олигомеризации, полимеризации, а также полупродуктов в лакокрасочной промышленности.The present invention relates to the field of organic chemistry, specifically to a method for producing (Z) -1,2-dialkyl-1,2-diethylethylenes of the general formula (1)

where R = nC ₃ H ₇ , nC ₄ H ₉
Unsaturated hydrocarbons and their derivatives can be used as starting monomers in the processes of oligomerization, polymerization, as well as intermediates in the paint and varnish industry.

Известный способ не позволяет получать (Z)-1,2-диалкил-1,2-диэтилэтилены.A known method (R. D. Gardner, M. Narayana, J. Org. Chem., 1961, V.26, P. 3518) for the production of tetra-substituted olefins by the interaction of hemi-dihalides with metallic magnesium in ether according to the scheme

The known method does not allow to obtain (Z) -1,2-dialkyl-1,2-diethylethylene.

Известный способ не позволяет получать (Z)-1,2-диалкил-1,2-диэтилэтилены.A known method (E. Negishi, N. Okukado, AO King, DE Van Horn, B.J. Spiegel, J. Am. Chem. Soc., 1978, V.100, P.2254) for producing tetrasubstituted olefins by reacting disubstituted acetylenes with with an equimolar amount of trimethylaluminum (Me ₃ Al) in the presence of catalytic amounts of zirconacenedic dichloride (Cp ₂ ZrCl ₂ ) at room temperature, followed by the addition of alkenyl, aryl or alkynyl halides, an equimolar amount of zinc chloride (ZnCl ₂ ), catalytic amounts of palladium acetylacetonate nickel (Pd (acac) ₂ or Ni (acac) ₂ ) and triphenylphosphine (Ph ₃ P) according to the scheme

The known method does not allow to obtain (Z) -1,2-dialkyl-1,2-diethylethylene.

 A new process for the preparation of (Z) -1,2-dialkyl-1,2-diethylethylenes is proposed.

The essence of the method consists in the interaction of dialkyl substituted acetylenes RC≡CR (octin-4, decina-5) with triethylaluminum (Et ₃ Al) in the presence of catalytic amounts of zirconacenedichloride (Cp ₂ ZrCl ₂ ), taken in a molar ratio of 10: (10-20): (0.1-0.5), respectively, mainly 10: 15: 0.3, at room temperature (23-25 ^o C) and atmospheric pressure in hexane with stirring for 8 hours, followed by addition to the reaction mass at a temperature of ~ 0 ^o With ethyltosylate (EtTs), taken in a molar ratio RC≡CR: EtTs = 10: (40-60), mostly 10:50, with mixed the reaction mass for 16-20 hours, preferably 18 hours, at room temperature (23-25 ^o C), followed by hydrolysis of the reaction mass with a solution of HC1. Get (Z) -1,2-dialkyl-1,2-diethylethylene 1 with a yield of 45-66%.

Использование в указанной реакции меньших количеств Еt₃Аl и этилтозилата (EtTs) приводит к снижению выхода целевого продукта 1. Использование в реакции больших количеств этилтозилата (EtTs) не приводит к существенному увеличению выхода целевого продукта 1. При более высокой температуре (например, 60^oС) выход целевых продуктов не увеличивается, а при меньшей температуре (например, 0^oС) снижается скорость реакции.

The use of smaller amounts of Et ₃ Al and ethyltosylate (EtTs) in this reaction leads to a decrease in the yield of target product 1. The use of large amounts of ethyltosylate (EtTs) in the reaction does not significantly increase the yield of target product 1. At a higher temperature (for example, 60 ^o C) the yield of the target products does not increase, and at a lower temperature (for example, 0 ^o C) the reaction rate decreases.

Without triethylaluminium and ethyltosylate (EtTs), the reaction does not proceed. In the absence of a catalyst of zirconacene dichloride (Cp ₂ ZrCl ₂ ), target products 1 are not formed.

Significant differences of the proposed method from the known:
1. In the known method, alkenyl, aryl or alkynyl halides are used, while ethyltosylate (EtTs) is used in the present method.

2. In the known method, the catalysts used are zirconacene dichloride (Cp ₂ ZrCl ₂ ), palladium or nickel acetylacetonate (Pd (acac) ₂ or Ni (acac) ₂ ) in the presence of zinc chloride cocatalyst, while the proposed catalyst only uses zirconac dichloride (Cp ₂ ZrCl ₂ ).

 4. The proposed method allows to obtain (Z) -1,2-dialkyl-1,2-diethylethylene, whereas by the known method, 1,2,2-trialkyl-1-alkenyl (aryl, alkynyl) ethylenes are formed.

The advantages of the proposed method:
1. In contrast to the known methods, the proposed one allows to obtain (Z) -1,2-dialkyl-1,2-diethylethylenes 1 from disubstituted acetylenes with high regio- and stereoselectivity.

The method is illustrated by examples:
EXAMPLE 1. In a 50 ml glass reactor mounted on a magnetic stirrer, in an inert gas atmosphere, 10 ml of hexane, 10 mmol of decin-5, 15 mmol of Et ₃ Al and 0.3 mmol of Cp ₂ ZrCl _{2 were} charged, stirred for 8 hours at room temperature (23-25 ^o C). At a temperature of ~ 0 ^° C, 50 mmol of ethyltosylate (EtOTs) are added to the reaction mass and the reaction mass is stirred for 18 hours at room temperature (23-25 ^° C). The reaction mass is hydrolyzed with a solution of HCl, the organic layer is separated from the aqueous. (Z) -1,2-di (n-butyl) -1,2-diethylene is isolated from the organic layer in 59% yield.

Спектр ЯМР ¹³С (δ, м.д.): 14,15 (Cl), 24,43 (С2), 31,06 (С3), 31,64 (С4), 134,46 (С5), 23,19 (С6), 13,89 (С7). M⁺ 196.Spectral characteristics of (Z) -1,2-dialkyl-1,2-diethylethylene

¹³ C NMR spectrum (δ, ppm): 14.15 (Cl), 24.43 (C2), 31.06 (C3), 31.64 (C4), 134.46 (C5), 23, 19 (C6), 13.89 (C7). M ⁺ 196.

 Other examples confirming the method are given in the table.

All experiments were carried out at room temperature (23-25 ^o C). Hexane in an amount of 10 ml was used as a solvent.

Claims (1)

The method of obtaining (Z) -1,2-dialkyl-1,2-diethylethylenes General formula

where R = nC ₃ H ₇ , nC ₄ H ₉ ,
characterized in that the dialkyl substituted acetylenes of the formula RC-CR interact with triethylaluminum (Et ₃ Al) in the presence of a catalyst of zirconacene dichloride (Cp ₂ ZrCl ₂ ) in the molar ratio RC-CR: Et ₃ Al: Cp ₂ ZrCl ₂ = 10: (10:20 ) :( 0.1-0.5) under normal conditions in hexane with stirring for 8 hours, followed by the addition of ethyltosylate (EtTs) in a molar ratio RC≡CR: EtTs = 10 to the reaction mass at 0 ^° С : (40-60) with stirring the reaction mass for 16-20 hours at room temperature, followed by hydrolysis of the reaction mass hydrochloric acid.

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