Phosphite-imidazole catalyzed N -formylation and N -acylation of amines.

A novel and convenient method for the N -formylation reaction of amines with DMF as a formylating agent has been developed, utilizing a catalytic amount of diethyl phosphite/imidazole. Diethyl phosphite, as a nucleophilic catalyst, plays a significant role in this conversion. The presented method has a broad substrate scope, and various N -formyl products were obtained in good to excellent yields. Moreover, by using DMA instead of DMF, the N -acetylation reaction was also successful. The reaction of o -phenylenediamines with DMF afforded the corresponding benzimidazoles. Furthermore, N -sulfonyl amidines were obtained in good to excellent yields by the reaction of sulfonamides with DMF under similar conditions.