Domino Synthesis of Tetrasubstituted Thiophenes from 1,3-Enynes with Mercaptoacetaldehyde

摘要

Domino synthesis of tetrasubstituted thiophenes is described from 1,3-enynes and mercapto-acetaldehyde using DABCO at room temperature via a Michael addition, 5-exo-dig carboannulation, and oxidation sequence under air. The broad substrate scope and mild reaction conditions are significant practical features.