Cp*Ir complex bearing a flexible bridging and functional 2,2’-methylenebibenzimidazole ligand as an auto-tandem catalyst for the synthesis of N-methyl tertiary amines from imines via transfer hydrogenation/N-methylation with methanol

Abstract A Cp*Ir complex bearing a flexible bridging and functional 2,2’-methylenebibenzimidazole ligand was designed, synthesized, and found to be a general and efficient auto-tandem catalyst for the synthesis of N-methyl tertiary amines from imines via transfer hydrogenation/N-methylation with methanol as both hydrogen source and methylating reagent. In the presence of [Cp*Ir(2,2’-CH2BiBzImH2)Cl][Cl], a range of desirable products were obtained in high yields with nearly complete selectivities. The reaction is highly attractive due to the highly atom economy, and minimal consumption of chemicals and energy. Notably, this research exhibits new potential of metal-ligand bifunctional catalysts for the activation of methanol as C1 source for organic synthesis.