Synthesis of multi-substituted pyrroles using enamides and alkynes catalyzed by Pd(OAc)(2) with molecular oxygen as an oxidant

A cyclization reaction between enamides and alkynes catalyzed by palladium(II) acetate is described. In this method, the molecular oxygen serves as an efficient oxidant for the Pd(II)/Pd(0) catalytic cycle. The simple reaction conditions permit this methodology to be used as a general tool for the preparation of multi-substituted pyrroles.