Ytterbium and silver co-catalyzed synthesis of pyrrole-fused bicyclic skeletons from enynones and isocyanides

An unusual cascade reaction of isocyanide and enynone using Yb/Ag cooperative catalysis as a key step has been disclosed. The present strategy enables the double isocyanide insertion and subsequent 5-endo-dig cyclization, thus providing a quick access to structurally complex pyrrole-fused heterocycles.