Friedel-Crafts Type Alkylation of 1,2,3,4,5,6,7,8-Octahydroanthracene with Vinylchlorosilanes: Synthesis of Mono, Bis[2-(chlorosilyl)ethyl]-1,2,3,4,5,6,7,8-octahydroanthracenes

摘要

Friedel-Crafts alkylation reaction of an isomeric mixture of 1,2,3,4,5,6,7,8- (2) and 1,2,3,4,5,6,7,8-octahydrophenanthrene (2`) with excess vinylchlorosilanes such as vinyl(methyl)dichlorosilane (1a) and vinyltrichlorosilane (1b) in the presence of aluminum chloride catalyst at 80 ∩ gives only one dialkylated products, 9,10-bis[2-(chlorosilyl)ethyl]-1,2,3,4,5,6,7,8-octahydroanthrenes [(Cl<sub>2</sub>XSiCH<sub>2</sub>CH<sub>2</sub>)<sub>2</sub>C<sub>14</sub>H<sub>16</sub>: X = Me (4a), Cl (4b)] in good yields, but 9,10-bis[2-(chlorosilyl)ethyl]-1,2,3,4,5,6,7,8-octahydrophenanthrenes are not obtained. However, monoalkylation of 2 with 1 affords a mixture of both isomeric compounds, 9-[2-(chlorosilyl)ethyl]-1,2,3,4,5,6,7,8-octahydroanthracenes 3 and -phenanthrenes 3`. The yield of product 3` is always higher than that of 3. When a mixture of 3 and 3` is alkylated again with 1, only product 4 without phenanthrene type compounds is obtained, indicating that the isomerizations between 2 and 2`, or 3 and 3`occur under the alkylation condition. The alkylation with dimethylvinylchlorosilane or trimethylvinylsilane did not proceed. The structure of 4a is determined by X-ray single crystal diffraction analysis.