Iodine??Catalyzed, Stereo??and Regioselective Synthesis of 4??Arylidine??4H??benzo [d][1, 3] oxazines and their Applications for the Synthesis of Quinazoline 3??Oxides
Abstract 4-Benzylidene-2-aryl-4H-benzo [d][1, 3] oxazines have been synthesized with high stereoselectivity and regioselectivities from 2-alkynylbenzamides in the presence of a catalytic amount of I 2. In the reaction mechanism, iodine plays a key role in two different aspects as a catalyst, such as to activate the alkyne with the iodinium donor which triggers the cascade, and then as a proper acid source to facilitate catalyst recovery. The ...
