o-Acetoxylation of oxo-benzoxazines via C-H activation by palladium(ii)/aluminium oxide

Direct activation of sp(2) C-H bonds by a palladium catalyst has received significant attention in organic chemistry. However, most of these C-H activation reactions are carried out in hazardous solvents. Herein we report a novel solvent-free direct sp(2) C-H bond functionalization (oxygenation) method using Pd(ii)/Al2O3 catalysis of oxo-benzoxazine derivatives with good to excellent yields, and demonstrate its application in the synthesis of pharmaceutically important compounds.