Chelation-assisted carbonylation reactions catalyzed by Rh and Ru complexes*

This account reviews chelation-assisted carbonylation reactions catalyzed by late transition metals. New carbonylation reactions are achieved with these catalysts in the presence of pyridin-2-ylmethanol and pyridin-2-ylmethylamine. The reactions involve activation of O−H and N−H bonds, coordination of the pyridine nitrogen to Rh being essential for the reaction to proceed. In addition, a new type of carbonylation of the ortho C−H bonds in aromatic amides in which the pyridin-2-ylmethylamino moiety functions as a bidentate directing group, is demonstrated. In this reaction, a dinuclear ruthenium complex was isolated from a stoichiometric reaction of amide and Ru3(CO)12, in which amide binds to one Ru atom in the expected N,N fashion and the carbonyl oxygen binds to the other Ru atom as an O-donor. These studies indicate that chelation methodology is useful for new types of carbonylation reaction, which cannot be achieved by non-chelation systems.