Highly Regioselective Dichalcogenation of Alkenyl Sulfonium Salts to Access 1,1-Dichalcogenalkenes
1College of Materials, Chemistry and Chemical Engineering, Key Laboratory of Organosilicon Chemistry and Material Technology, Ministry of Education, Hangzhou Normal University, Hangzhou, Zhejiang 311121, China.
Abstract:
An unprecedented geminal olefinic dichalcogenation of alkenyl sulfonium salts with dichalcogenides ArYYAr (Y = S, Se, Te) is reported, providing various trisubstituted 1,1-dichalcogenalkenes [Ar1CH = C(YAr2)2] in a highly selective manner under mild and catalyst-free conditions. The key process involves the formation of two geminal olefinic C-Y bonds via sequential C-Y cross-coupling and C-H chalcogenation. A mechanistic rationale is further supported by control experiments and density functional theory calculations.
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