ZnO nanoparticles catalyzed C–N bond-forming reactions: A highly efficient protocol to convert electron-deficient anilines to formanilides

Abstract

Formanilides are important intermediates for the synthesis of biologically and pharmaceutically important compounds. Formanilides are synthesized by the reaction between an aromatic amine and a formylating agent. But the conversion of highly electron-deficient anilines to formanilides is expensive and sometimes time-consuming with poor yields. Herein, we report a protocol for the conversion of electron-deficient anilines to formanilides at room temperature using ZnO nanoparticles (NPs). The ZnO NPs of different shapes have been synthesized by conventional co-precipitation techniques and are characterized fully using different microscopic, diffractometric and spectroscopic techniques. The developed protocol is simple, green, inexpensive, and highly efficient. The products can be conveniently separated from the reaction mixture without using the conventional tedious and expensive chromatographic techniques. The protocol is effective for a wide range of substituted anilines, aliphatic amines and heterocycles with moderate to excellent yield. The catalyst is highly stable and is reusable up to the 5^th cycle without loss of catalytic activity.