Lewis base promoted [4 + 2] annulation of o-acylamino-aryl MBH carbonates with isatin

Abstract

This study reports the first [4 + 2] annulation reaction of o-acylamino-aryl MBH carbonates and isatin. This approach has enabled the first synthesis of the 1,4-dihydrospiro[benzo[d][1,3]oxazine-2,4′-oxindoles] scaffold, achieving yields of up to 98%.