An Inverse Electron Demand Azo-Diels–Alder Reaction of o-Quinone Methides and Imino Ethers: Synthesis of Benzocondensed 1,3-Oxazines

摘要

We have studied the reactions of o -quinone methide precursors with imino ethers. The reaction provides a versatile route to substituted 1,3-benzoxazines. The proposed reaction mechanism involves the generation of the o -quinone methide intermediates, imino-Diels–Alder reaction, and elimination. This cascade process is a rare example of the participation of imino ethers as dienophiles.