Alkenyl bromides: useful coupling partners for the palladium-catalysed coupling with heteroaromatics via a C–H bond activation

Alkenyl bromides were found to be useful reactants for the palladium-catalysed direct C–H activation/functionalisation reaction of heteroaromatics such as benzoxazole or benzothiazole. Moderate to good yields of coupling products were obtained using both α- and β-substituted alkenyl bromides or even the trisubstituted alkenyl bromide 2-bromo-3-methylbut-2-ene. This reaction is environmentally attractive as it provides only HX associated to the base as a by-product.