Fabrication of Nitrogen-Doped Carbon Supported Moo2/Mo2c Hybrid Catalyst for Efficient Oxidative Coupling of Primary Amines to Imines

Abstract

Direct oxidative coupling of primary amines is an efficient method for preparation of complex imines. The key steps are both oxidant activation and dehydrogenation of primary amine into NH-imine intermediate. Traditional reaction system was always subject to harsh conditions. Herein, a MoO 2 /Mo 2 C hybrid catalyst supported on N-doped carbon was synthesized by simple annealing of cellulose, g-C 3 N 4 and molybdic acid. The prepared MoO 2 /Mo 2 C was featured with moderate mesoporosity, uniform metallic nanoparticles, and rich oxygen-vacancies. It showed excellent efficiency (99% imine yield) and good reusability for oxidative self-coupling of benzylamine to N-benzylbenzaldimine under mild conditions (85 °C, 3 h, 1 bar O 2 ). In addition, the catalyst MoO 2 /Mo 2 C also exhibited a universal applicability for oxidative coupling of other primary amines to imines with impressive conversion and satisfying target product selectivity. This method provides an efficient and environment friendly strategy for catalytic synthesis of complex imines from primary amines

Keywords: amines, imines, oxidative self-coupling, molybdenum carbide, oxygen vacancy