Rhodium-Catalyzed Dehydrogenative Coupling of Phenylheteroarenes with Alkynes or Alkenes

Benzo-fused tri- to heptacyclic heteroarenes were effectively constructed by the rhodium-catalyzed dehydrogenative coupling of phenylheteroarenes with alkynes. Using alkenes as coupling partners, dehydrogenative alkenylation took place selectively on the phenyl moiety of phenylheteroarenes. Several experiments with deuterium-labeled substrates indicated that double C–H bond cleavages take place even in the reaction with alkenes

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