Cascade Trisulfur Radical Anion (S<sub>3</sub><sup>•–</sup>) Addition/Electron Detosylation Process for the Synthesis of 1,2,3-Thiadiazoles and Isothiazoles
作者:Bei-Bei Liu、Hui-Wen Bai、Huan Liu、Shun-Yi Wang、Shun-Jun Ji
DOI:10.1021/acs.joc.8b01450
日期:2018.9.7
Trisulfur radical anion (S3•–) mediated reactions with in situ formed azoalkenes and α,β-usaturated N-sulfonylimines for the construction of 1,2,3-thiadiazoles and isothiazoles has been developed. S3•– is in situ generated from potassium sulfide in DMF. These two approaches provide a new, safe, and simple way to construct 4-subsituted 1,2,3-thiadiazoles, 5-subsituted 1,2,3-thiadiazoles, and isothiazole
Simple and commercially available starting materials, a broad substrate scope, and excellent functional group tolerability make this strategy practical for applications. Furthermore, 1,2,3-thiadiazole synthesis was realized by using potassium thiocyanate as an odorless sulfur source.
The reaction of 1,2,3-thiadiazoles with base. I. A new route to 1-alkynyl thioethers
作者:R. Raap、R. G. Micetich
DOI:10.1139/v68-179
日期:1968.4.1
unsubstituted in the 5-position, and a strong base such as an organolithium compound, sodamide, sodium methylsulfinyl carbanion, or potassium t-butoxide results in cleavage of the thiadiazole ring system with evolution of nitrogen and formation of alkalimetal alkynethiolate. Subsequent addition of an alkyl or acyl halide to the reaction mixture produces 1-alkynyl thioethers. 4-(5-Phenyl-1,2,3-thiadiazolyl)lithium