Synthesis of fluoroaromatic compounds from the cyclopentadiene derivatives by reactions with chlorofluorocarbene under phase-transfer catalysis

Abstract

The reactions of CHCl 2F with cyclopentadiene derivatives in the presence of aqueous KOH and triethylbenzylammonium chloride (TEBA) at −10 − +5∘ leads to the formation of fluoroaromatic compounds with a good yield: ▪ The synthesis involves addition of chlorofluorocarbene to dienes, resulting in corresponding cyclopropane adducts (derivatives of 6-chloro-6-fluorobicyclo[3.1.0]hex-2-ene and subsequent aromatization of the latter, proceeding via expansion of the cyclopentene ring and elimination of hydrogen chloride.