Base-mediated [3+2] annulation of trifluoroacetimidoyl chlorides and isocyanides: An improved approach for regioselective synthesis of 5-trifluoromethyl-imidazoles

A t-BuOK-mediated [3 + 2] cycloaddition reaction of trifluoroacetimidoyl chlorides and active methylene isocyanides for the synthesis of 5-trifluoromethyl-imidazoles has been developed. Under mild reaction conditions, the transformation proceeds smoothly in the presence of t-BuOK to afford an array of structurally diverse 5-trifluoromethyl-imidazoles with high efficiency.