DIRECT CARBONYLATION AT A C-H BOND CATALY ZED BY TRANSITION-METAL COMPLEXES

Transition-metal-catalyzed carbonylation with cleavage of a C-H bond i s described. The reactions described are (i) carbonylation at the C-H bond alpha to the ring nitrogen in imidazoles (ii) carbonylation at th e C-H bond gamma to the ring nitrogen in pyridylbenzenes, aromatic imi nes, and aryloxazolines (iii) carbonylation at the olefinic C-H bond i n pyridylolefines (iv) carbonylation at the sp(2) C-H bond in a pipera zine ring. Coordination of a directing group such as nitrogen or oxyge n functionalities to transition metals, such as ruthenium and rhodium, promotes site selective cleavage of a C-H bond.