1,3-dipolar cycloaddition-decarboxylation reactions of an azomethine ylide with isatoic anhydrides: Formation of novel benzodiazepinones

Abstract

A nonstabilized azomethine ylide reacts with a wide range of substituted isatoic anhydrides to afford novel 1,3-benzodiazepin-5-one derivatives, which are generally isolated in high yield. The transformations involve 1,3-dipolar cycloaddition reactions of the ylide with the anhydrides to give transient, and in a representative case spectroscopically observable, oxazolidine intermediates that undergo ring-opening-decarboxylation-ringclosing reaction cascades to yield the 1,3-benzodiazepin-5-one products. © 2011 American Chemical Society.