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

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. [ABSTRACT FROM AUTHOR]