Rhodium-Catalyzed C3-Selective Alkenylation of Substituted Thiophene-2-carboxylic Acids and Related Compounds

The regioselective C3-alkenylation of 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