The ruthenium-catalyzed oxidative vinylation of thiophene-2-carboxylic acids with alkenes efficiently proceeds through directedC−Hbond cleavage to give the corresponding 3-vinylated products. Similarly, benzothiophene-, benzofuran-, pyrrole-, and indolecarboxylic acids also undergo regioselective vinylation.
thiophene-2-carboxylic acids can be achieved effectively via rhodium/silver-catalyzed oxidative coupling with alkenes, unaccompanied by decarboxylation. A wide range of substrates including brominated thiophenecarboxylic acids and furan-2-carboxylic acids can be employed together with styrenes as well as acrylates. The present catalyst system is also applicable to ortho-alkenylation of benzoic acids.