Copper-(II) Catalyzed N-Formylation and N-Acylation of Aromatic, Aliphatic, and Heterocyclic Amines and a Preventive Study in the C-N Cross Coupling of Amines with Aryl Halides

A Cu-(II) catalyzed N-formylation and N-acylation of amines with moderate to excellent yields, using N, N-dimethyl formamide (DMF) and N, N-dimethyl acetamide (DMA) as a formyl and acylating sources in the presence of 1,2,4-triazole is reported. This novel, highly efficient and simple protocol shows broad substrate scope for aliphatic, aromatic, and heterocyclic amines. In addition, the conditions to prevent N-formylation and N-acylation impurities in the C-N cross coupling of amines and aryl halides are described typically when DMF and DMA are used as solvents, with various catalysts, ligands, and bases.