Synthesis of multisubstituted furans, pyrroles, and thiophenes via ynolates

An efficient synthetic method for the preparation of multisubstituted furans, thiophenes, and pyrroles using ynolates was developed. This novel formal [4 + 1] annulation by C2-C3 and C3-C4 bond formations includes cycloaddition, cyclization, decarboxylation, and dehydration as key steps.