synthesis of secondary and tertiaryamines has been achieved by means of Cp*Ir-catalyzed multialkylation of ammonium salts with alcohols without solvent: the reactions of ammonium acetate with alcohols gave tertiaryamines exclusively, while those of ammonium tetrafluoroborate afforded secondary amines selectively. Using this method, secondary 5- and 6-membered cyclic amines were synthesized from ammonium
A New Atom-Economical and Selective Synthesis of Secondary and Tertiary Alkylamines by Means of Cp*Iridium Complex Catalyzed Multiple N-Alkylation of Ammonium Salts with Alcohols without Solvent
A new atom-economical and selective synthetic method for secondary and tertiary alkylamines has been achieved by means of (pentamethylcyclopentadienyl)iridium (Cp*Ir) complex catalyzed multiple N-alkylations of ammonium salts with primary and secondary alcohols without solvent.
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)][1](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.