The environmentally friendly and efficient method reported here is highly promising for constructing 1,4-benzoxazine derivatives via C–C/C–O cross coupling cyclization pathways. The present protocol exhibits a wide range of substrate scope and functional-group tolerance.
Palladium-catalyzed chalcogenation of benzoxazines has been achieved. The reaction shows broad substrate scope and late-stage functionalization potential. The regioselective product formation occurrs through a palladacycle.
A [3 + 2]-spiroannulation of 2-aryl-1,4-benzoxazines with 4-hydroxy-2-alkynoates has been developed for the synthesis of highly rigid spirolactones through a cascade of ortho-C–H annulation followed by lactonization.
The formation of quinoxalines, 2-aryl-1,4-benzoxazines and 2-aryl-1,4-thiazines by reacting 1,2-diaminobenzenes and 1,2-aminophenols/thiophenols with styrenes in CPB-micellar medium is reported.
This is the first report on polymerizable 3,1-benzoxazine, providing a new type of resin for preparing high performance thermosets.