Efficient stereoselective synthesis of benzoxazines via copper-catalyzed three-component coupling reactions

摘要

A convenient one-pot synthesis of 1,4-benzoxazines via three-component coupling and subsequent O-cyclization is reported. The present reaction provides an efficient protocol to functionalized 1,4-benz-oxazine derivatives in good to high yields from aldehydes, amines and alkynes. Furthermore, the O-annu-lation process is completely regio- and stereoselective, only the six-membered rings and its Z-isomers were obtained.