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.