Synthesis, Structures of Benzoxazolyl Iridium(III) Complexes, and Applications on C–C and C–N Bond Formation Reactions under Solvent-Free Conditions: Catalytic Activity Enhanced by Noncoordinating Anion without Silver Effect

Several new bisbenzoxazolyl iridium(III) complexes have been synthesized and characterized through X-ray crystallography. These complexes exhibit excellent catalytic activity in C–C and C–N bond formation reactions from the alkylation of amine with amine, amine with alcohol, ketone with alcohol, and alcohol with alcohol through a borrowing hydrogen reaction. Moreover, these iridium(III) complexes are effective catalysts for the alkylation of amine with alcohol and ketone with alcohol under solvent-free conditions. The catalytic activity of these complexes is greatly enhanced by noncoordinating, while the experiments have excluded the possibility of a “silver effect” (bimetallic catalysis or silver-assisted metal catalysis) from the experiments.