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Cercosporin-Photocatalyzed [4+1]- and [4+2]-Annulations of Azoalkenes Under Mild Conditions
Published on: July 17, 2020
Access to 4-substituted isothiazoles through three-component cascade annulation and their application in C-H
Guoling Huang1, Jian Li, Xiaoliang Ji
1School of Biotechnology and Health Sciences, Wuyi University, Jiangmen, Guangdong Province 529090, China. leeyib268@126.com wyuchemhyb@126.com.
Abstract:
The use of potassium ethyl xanthate (EtOCS2k) as a sulfur atom donor enabled the transition-metal-free [3 + 1 + 1] cascade annulation of isopropene derivatives with NH4I in DMSO/H2O, affording various 4-substituted isothiazoles in moderate to good yields with good functional group compatibility. Furthermore, Pd and Ag-catalyzed C5-H-selective direct oxidation dimerization of 4-substituted isothiazoles afforded 5,5'-bisisothiazoles. This series of reactions included the formation of new C-S, C-N, N-S, and C-C bonds via cascade addition, annulation, and direct C-H activation under mild conditions.
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