Efficient synthesis of trifluoromethyl-containing vicinal chlorohydrins and dichlorides via Mn-mediated chlorohydroxylation and dichlorination of α-(trifluoromethyl)styrenes

Abstract

An efficient method for the synthesis of trifluoromethyl-containing vicinal chlorohydrins and dichlorides via Mn-mediated chlorohydroxylation and dichlorination of α-(trifluoromethyl)styrenes using Na₂S₂O₈ as an oxidant and NaCl as a chlorine source was developed. The distribution of α-hydroxy-α-trifluoromethyl-β-chlorohydrins and α-trifluoromethyl dichlorides was highly dependent on the amount of NaCl and Na₂S₂O₈, as well as the solvent employed. The addition of water would be beneficial for the formation of chlorohydrins. The reaction mechanism involves an electrophilic addition of a chloronium ion to electron-deficient α-(trifluoromethyl)styrenes.