Copper-Catalyzed Annulative Coupling of S,S-Disubstituted Enones with Diazo Compounds to Access Highly Functionalized Thiophene Derivatives

An efficient protocol toward fully substituted thiophenes and thieno­[2,3-b]­thiophenes has been developed through CuCl2-catalyzed annulative coupling of S,S-disubstituted enones with diazo compounds under mild conditions. Tetrasubstituted thiophenes and thieno­[2,3-b]­thiophenes were efficiently accessed by variation of the feed ratio of the reactants in good to excellent yields, respectively. The synthetic methodology has demonstrated the potential for the construction of diverse thiophene derivatives.

本研究开发了一种可用于制备全取代噻吩（thiophenes）与噻吩并[2,3-b]噻吩（thieno[2,3-b]thiophene）的高效合成方案：在温和条件下，通过氯化铜(II)（CuCl₂）催化S,S-二取代烯酮与重氮化合物的环化偶联反应实现。通过调整反应物的投料比，可分别高效得到四取代噻吩与噻吩并[2,3-b]噻吩，产物收率良好至优异。该合成方法展现了构建多样化噻吩类衍生物的应用潜力。