Cobalt-Catalyzed Acceptorless Dehydrogenative Coupling of Primary Alcohols to Esters.

A novel catalytic system with a tripodal cobalt complex is developed for efficiently converting primary alcohols to esters. KO tBu is found essential to the transformation. A preliminary mechanistic study suggests a plausible reaction route that involves an initial Co-catalyzed dehydrogenation of alcohol to aldehyde, followed by a Tishchenko-type pathway to ester mediated by KO tBu.

Tripodal N,P Mixed-Donor Ligands and Their Cobalt Complexes: Efficient Catalysts for Acceptorless Dehydrogenation of Secondary Alcohols.

A new tetradentate tripodal ligand, iPrPPPNHPyMe, and the cobalt complexes were synthesized and characterized. The well-defined cobalt complexes efficiently catalyzed acceptorless dehydrogenation of secondary alcohols into ketones.