Direct Approach to Multi-substituted Pyrroles from 2-Propynylamine and 1,3-Diketone or β-Keto Ester Using Bi(OTf)3 Catalyst

Bi(OTf)(3) was found to be a good catalyst for the direct synthesis of multi substituted pyrroles from the readily accessible 2-propynylamine and activated methylene compounds in which the bismuth played two roles: sigma- and pi-activations.