A cascade approach to fused indolizinones through Lewis acid-copper(i) relay catalysis
A relay catalytic cascade process involving Lewis acid triggered ring-opening of cyclopropyl ketones with nitriles, the copper(i)-catalyzed Ritter process, and acid-promoted N-acyliminium ion cyclization is described, which efficiently provides thieno-, furano-, and benzo-indolizinones in moderate to good yields. The Royal Society of Chemistry 2013.