α-(Trifluoromethyl)ethenyl boronic acid as a useful trifluoromethyl containing building block. Preparation and palladium-catalysed coupling with aryl halides

α-(Trifluoromethyl)ethenyl boronic acid was conveniently prepared from the reaction of readily available 2-bromotrifluoropropene with alkyl borate and magnesium in one-pot. This boronic acid can undergo palladium-catalysed coupling reactions with aryl halides to afford a series of useful α-(trifluoromethyl)styrene derivatives in high yield.