One‐Pot Synthesis of 2,3,5‐Trisubstituted Thiophenes through Three‐Component Assembly of Arylacetaldehydes, Elemental Sulfur, and 1,3‐Dicarbonyls

The three‐component reaction for the synthesis of 2‐arylthiophenes has been developed. Easily available arylacetaldehydes, 1,3‐dicarbonyls, and elemental sulfur were directly assembled through cascade condensation/ annulation under base conditions. The present protocol provides a facile entry to 2,3,5‐trisubstituted thiophenes with moderate to excellent yields and good functional group tolerance. magnified image