Two Reaction Modes of Pyridinium 1,4-Zwitterionic Thiolates with Sulfenes: Synthesis of 3H-1,2-Dithiole 2,2-Dioxides, 1,9a-Dihydropyrido[2,1-c][1,4]thiazines, and Indolizines

Bin Cheng*, Yuntong Li, Xinping Zhang, Shengguo Duan, Hui Li, Yixuan He, Yun Li, Taimin Wang* and Hongbin Zhai*

*Institute of Marine Biomedicine/Hoffmann Institute of Advanced Materials, Shenzhen Polytechnic, Shenzhen 518055, China, Email: chengbinszpt.edu.cn, wangtmszpt.edu.cn, zhaihbpkusz.edu.cn

B. Cheng, Y. Li, X. Zhang, S. Duan, H. Li, Y. He, Y. Li, T. Wang, H. Zhai, Org. Lett., 2020, 22, 5817-5821.

DOI: 10.1021/acs.orglett.0c01888

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Abstract

Pyridinium 1,4-zwitterionic thiolates with sulfenes generated in situ provide either 3H-1,2-dithiole 2,2-dioxides via a formal [3 + 2] pathway from alkylmethanesulfonyl chlorides, while 1,9a-dihydropyrido[2,1-c][1,4]thiazines were obtained via a stepwise [(5 + 2) - 1] pathway from arylmethanesulfonyl chlorides. 1,9a-dihydropyrido[2,1-c][1,4]thiazines can be converted into indolizines.

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proposed mechanism

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Key Words

S-heterocycles

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ID: J54-Y2020