Recent Advances for the Synthesis of 4H‐3,1‐Benzoxazines via Annulation of Olefinic Amides

Abstract

4H‐3,1‐Benzoxazines represent important six‐membered heterocyclic compounds in organic chemistry, and the intramolecular cyclization of olefinic amides with various radical species or electrophiles has been established as an efficient strategy for the synthesis of 4H‐3,1‐benzoxazines. Recently, increasing efforts have been devoted to developing more efficient and sustainable synthetic approaches toward 4H‐3,1‐benzoxazines under various reaction conditions. In this review, we provided an overview of the recent progress for the construction of 4H‐3,1‐benzoxazines via annulation of olefinic amides. A series of different substituted 4H‐3,1‐benzoxazines were synthesized through cyclization of olefinic amides with different radical species or electrophiles are surveyed herein. We also discussed the substrate scope and mechanistic details of these reactions.