Synthesis of novel 4-substituted 1, 2, 3-thiadiazoles via iodine-catalyzed cyclization reactions. (2nd March 2021)

• Record Type: Journal Article
• Authors: Li, Weiwei; Li, Xuezhen; Feng, Yijiao; Liu, Ping; Ma, Xiaowei; Zhao, Jixing
• Is Part Of: Tetrahedron letters. Volume 66(2021)
• Publication Date: 2021-03-02
• Subjects: Cyclization -- Iodine-catalyzed -- 1, 2, 3-thiadiazole -- Selective -- Synthesis; Chemistry, Organic -- Periodicals; 547.005
• DOI: 10.1016/j.tetlet.2021.152824
• Languages: English
• ISSNs: 0040-4039

Abstract

Graphical abstract: Highlights: An efficient iodine-catalyzed the reaction of the ester-substituted N -tosylhydrazones with S8 was developed. Various novel 4-substituted 1, 2, 3-thiadiazoles were synthesized. The synthetic potential is demonstrated by gram-scale synthesis and further transformations. Abstract: Iodine-catalyzed the reaction of substituted methyl ketone N -tosylhydrazones with elemental sulfur has been developed. The cyclizations of the ester-substituted N -tosylhydrazone substrates proceeded smoothly under optimal reaction conditions, and the corresponding products 4-alkyl-1, 2, 3-thiadiazoles are obtained. For the reaction of 4-arylbutan-2-one of N -tosylhydrazone substrates, ( E )-4-styryl-1, 2, 3-thiadiazole derivatives were obtained with high selectivity through the control of reaction conditions. In addition, gram-scale synthesis and further transformation of the product were also investigated.