CuH-Catalyzed Selective N-Methylation of Amines Using Paraformaldehyde as a C1 Source.

Copper hydride (CuH) complexes have been proposed as key intermediates in synthesis and catalysis. Herein, we developed a highly efficient strategy for CuH-catalyzed N-methylation of aromatic and aliphatic amines using paraformaldehyde and polymethylhydrosiloxane (PMHS) under mild reaction conditions. The reaction proceeded smoothly without additives to furnish the corresponding N-methylated products using cyclic(alkyl)(amino)carbene (CAAC)CuH as a reaction intermediate, which results from a reaction between PMHS and (CAAC)CuCl.

Reductive amination of ketones/aldehydes with amines using BHN(CH) as a reductant.

Herein, we report the first example of efficient reductive amination of ketones/aldehydes with amines using BHN(CH) as a catalyst and a reductant under mild conditions, affording various tertiary and secondary amines in excellent yields. A mechanistic study indicates that BHN(CH) plays a dual function role of promoting imine and iminium formation and serving as a reductant in reductive amination.