Synthesis of benzoxazine and 1,3-oxazine derivatives via ligand-free copper(I)-catalyzed one-pot cascade addition/cyclization reaction

A novel and efficient synthesis of benzoxazine and 1,3-oxazine derivatives via ligand-free copper(I)-catalyzed one-pot cascade addition/cyclization reaction has been developed. A variety of carbodiimides coupled with o-halophenylmethanols and/or substituted (Z)-3-iodoprop-2-en-1-ols to give the corresponding products in moderate to excellent yields under the mild condition.