Sulfur-promoted, one-pot, and metal-free conversion of aromatic aldehydes to nitriles using an inorganic ammonium salt as the nitrogen source

Abstract

A simple protocol for the sulfur-promoted conversion of aromatic aldehydes to aromatic nitriles has been developed. This strategy enables the one-pot conversion of inexpensive and readily available aromatic aldehydes into highly valuable aromatic nitriles using a cheap inorganic ammonium salt as the nitrogen source in the absence of metals. Significantly, a broad scope of substrates was explored using this strategy, and various groups, including alkyl, alkoxyl, alkylthiol, hydroxyl, amino, aryl, alkenyl, cyano, carboxyl, and borate ester groups were tolerated, and good to excellent yields were achieved in most cases. Additionally, polycyclic aromatic aldehydes and heteroaromatic aldehydes also could be converted to the corre-sponding nitriles with satisfactory yields. This method can be utilized as a powerful tool for the cyanation of complex molecules.