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

We have studied the reactions of <i>o</i>-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 <i>o</i>-quinone methide intermediates, imino-Diels–Alder reaction, and elimination. This cascade process is a rare example of the participation of imino ethers as dienophiles