Synthesis of 1-trimethylsilyl-2-arylcyclohexenes: a new class of anionic synthons

摘要

The sequential synthesis of eleven novel 1-trimethysilyl-2-arylcyclohexenes 4a-k from 1-bromo-2-chlorocyclohexene (1) is reported. The Suzuki cross coupling of 1 with eleven aryl boronic acids 2a-k gave the 1-chloro-2-arylcyclohexenes 3a-k in >90% yields. Wurtz-Fittig coupling reaction of 3a-k with metallic sodium and chlorotrimethylsilane in anhydrous ether solvent afforded the novel anionic synthons: 1-trimethylsilyl-2-arylcyclohexenes 4a-k in 65-87% yields. The cyclic vinylsilanes 4a-j are liquids, and 1-trimethylsilyl-2-biphenylcyclohexene (4k) exists as a solid. The crystal structure of 4k is discussed. A plausible mechanism for the Wurtz-Fittig reaction and formation of vinylsilanes is highlighted. (C) 2016 Elsevier Ltd. All rights reserved.