Dehydrogenative Oxidation of Alcohols in Aqueous Media Catalyzed by a Water-Soluble Dicationic Iridium Complex Bearing a Functional N-Heterocyclic Carbene Ligand without Using Base

A dicationic iridium complex bearing a bidentate ligand that comprises N-heterocyclic carbene and a-hydroxypyridine moieties has been designed and synthesized. The complex exhibited high catalytic performance in aqueous media for the dehydrogenative oxidation of secondary alcohols to ketones accompanying the evolution of hydrogen. Furthermore, dehydrogenative transformation of primary alcohols to the carboxylic acids in aqueous media was also catalyzed by the complex without using base.