An enantioselective inverse-electron-demand imino Diels-Alder reaction.
The imino Diels-Alder reaction is an efficient method for the synthesis of aza-heterocycles. While different stereo- and enantioselective inverse-electron-demand imino Diels-Alder (IEDIDA) reactions have been reported before, IEDIDA reactions including electron-deficient dienes are unprecedented. The first enantioselective IEDIDA reaction between electron-poor chromone dienes and cyclic imines, catalyzed by zinc/binol complexes is described. The novel reaction provides a facile entry to a natural product inspired collection of ring-fused quinolizines including a potent modulator of mitosis.