Recyclable palladium-catalyzed carbonylative annulation of 2-iodoanilines with acid anhydrides: A practical synthesis of 2-alkylbenzoxazinones

A highly efficient heterogeneous palladium-catalyzed carbonylative annulation of 2-iodoanilines and acid anhydrides has been developed. The reaction proceeds effectively in toluene using N,N-diisopropylethylamine (DiPEA) as the base at 100 degrees C under 2 bar of CO and provides a novel, general, and practical method for the assembly of a wide variety of 2-alkylbenzoxazinones with high functional group tolerance and good to excellent yields. This supported palladium complex can be readily separated from the product and recovered by a simple filtration of the reaction solution and reused up to seven times with almost consistent catalytic efficiency.

Automated summary

A highly efficient heterogeneous palladium-catalyzed carbonylative annulation of 2-iodoanilines and acid anhydrides has been developed, providing a novel method for the assembly of 2-alkylbenzoxazinones with high functional group tolerance. The supported palladium complex used in the reaction can be easily separated, recovered, and reused up to seven times with consistent catalytic efficiency.