Development and Application of New Iridium Catalysts for Efficient Dehydrogenative Reactions of Organic Molecules

In this paper, development and application of iridium catalysts for dehydrogenative reactions including (1) dehydrogenative oxidation of alcohols into carbonyl compounds, (2) hydrogen storage systems based on the reversible interconversion between saturated N-heterocycles and unsaturated aromatic N-heterocycles by catalytic dehydrogenation and hydrogenation, and (3) efficient hydrogen production from methanolwater solution under very mild conditions, are reported. The key point of the study described in this paper is designing a series of catalysts based on the cooperation of a metal center and a functional ligand, which is based on reversible transformation of two catalytically active species (an iridium species bearing a-pyridonate-based functional ligand and an iridium species bearing a-hydroxypyridine-based functional ligand). Various novel iridium catalysts have been synthesized and a number of catalytic dehydrogenative reactions have been developed. In addition to providing new methods for organic synthetic chemistry, these investigations would contribute to the fields of environmental chemistry and sustainable energy research.