Stereoselective Synthesis of Functionalized Benzooxazepino[5,4- a]isoindolone Derivatives via Cesium Carbonate Catalyzed Formal [5 + 2] Annulation of 2-(2-Hydroxyphenyl)isoindoline-1,3-dione with Allenoates.

In this work, we present a strategy for the stereoselective synthesis of functionalized benzooxazepino[5,4- a]isoindolone derivatives via a Cs2CO3-catalyzed domino β-addition and γ-aldol reaction of 2-(2-hydroxyphenyl)isoindoline-1,3-dione derivatives with allenoates, which offers an avenue for a combination of the structural unity between benzooxazepine and isoindolone motifs in synthetically useful yields with high stereoselectivities under mild conditions. Remarkably, it is the first example of highly stereoselective Cs2CO3-catalyzed formal [5 + 2] annulation of 2-(2-hydroxyphenyl)isoindoline-1,3-dione with allenoates.