Multialkylation of Aqueous Ammonia with Alcohols Catalyzed by Water-Soluble Cp*Ir−Ammine Complexes

Novel water-soluble Cp*Ir−ammine complexes have been synthesized, and a new and highly atom-economical system for the synthesis of organic amines using aqueous ammonia as a nitrogen source has been developed. With a water-soluble and air-stable Cp*Ir−ammine catalyst, [Cp*Ir(NH₃)₃][I]₂, a variety of tertiary and secondary amines were synthesized by the multialkylation of aqueous ammonia with theoretical equivalents of primary and secondary alcohols. The catalyst could be recycled by a facile procedure maintaining high activity. A one-flask synthesis of quinolizidine starting with 1,5,9-nonanetriol was also demonstrated. This new catalytic system would provide a practical and environmentally benign methodology for the synthesis of various organic amines.