Copper-Catalyzed Electrophilic Amidation of Organotrifluoroborates with Use of N-Methoxyamides.

A copper-catalyzed electrophilic amidation of aryltrifluoroborates with use of N-methoxyamides is reported. The reaction shows high functional group compatibility derived from two distinct features: 1) the high stability of the N-methoxyamides and 2) the nonbasic mild conditions in the presence of LiCl. The developed method can also be applied to the synthesis of enamides, which are widely distributed in natural products. Preliminary mechanistic studies suggest that the initial step is the transmetalation of the aryltrifluoroborate by the assistance of LiCl, and the resulting aryl copper intermediate provides the anilide through non-SN 2 oxidative addition to the N-methoxyamide and subsequent reductive elimination.