Pyrrole synthesis through Cu-catalyzed cascade [3 + 2] spiroannulation/aromatization of oximes with azadienes†
We have disclosed a new synthetic method for the rapid assembly of poly-substituted pyrroles with readily accessible oximes and azadienes as the starting materials. The present approach generates an array of structurally new and interesting pyrroles in generally moderate to good yields with good functional group tolerance. This approach can also be utilized to modify some pharmaceuticals. Mechanistic investigations suggest that the reactions would involve a [3 + 2] spiroannulation and aromatization cascade process.