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Cercosporin-Photocatalyzed [4+1]- and [4+2]-Annulations of Azoalkenes Under Mild Conditions
Published on: July 17, 2020
Visible-Light-Induced [4+2] Annulation of Thiophenes and Alkynes to Construct Benzene Rings
Chunlan Song1, Xin Dong1, Zhongjie Wang1
1College of Chemistry and Molecular Sciences and The Institute for Advanced Studies (IAS), Wuhan University, Wuhan, 430072, Hubei, P. R. China.
Abstract:
The [4+2] annulation represents an elegant and versatile synthetic protocol for the construction of benzene rings. Herein, a strategy for visible-light induced [4+2] annulation of thiophenes and alkynes, to afford benzene rings, is presented. Under simple and mild reaction conditions, the ready availability and structural diversity of thiophenes and alkynes permit the facile synthesis of several substituted aromatic rings. Valuable drugs and amino acids are also well tolerated. Moreover, DFT calculations explain the high regioselectivity of the reaction.
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