Synthesis of benzo-annulated 1,3-oxazine derivatives through the multi-component reaction of arynes with N-heteroaromatics and aldehydes or ketones

A multi-component reaction involving arynes, N-heteroaromatic compounds (including pyridine, quinoline, and isoquinoline), and aldehydes or ketones for the synthesis of benzo-annulated 1,3-oxazine derivatives has been described. The whole process is carried out under mild conditions and furnishes the desired products in 35–85% yields. Furthermore, regioselectivity and diastereoselectivity can be observed when using 3-OMe aryne precursor in this reaction.