CaO-catalyzed Aerobic Oxidation of α-Hydroxy Ketones: Application to One-pot Synthesis of Quinoxaline Derivatives

Abstract

Abstract The aerobic oxidation of α-hydroxy ketones into α-diketones catalyzed by CaO is compared with the same reaction catalyzed by other metal oxides. The catalytic activities of the various metal oxides were proportional to their surface basicities. The direct conversion of α-hydroxy ketones into quinoxalines via CaO-catalyzed aerobic oxidation followed by in situ reaction with 1,2-diaminoaromatics is also achieved. Various types of quinoxalines were synthesized in the presence of the CaO catalyst and molecular oxygen. It was also found that the CaO catalyst was reusable without any loss of its catalytic activity.