4-Phenyl-1,2-dithiolium perchlorate reacts with ammonia in ethanol to yield 4-phenyl-isothiazole. The reaction is general for dithiolium salts. When unsymmetrical dithiolium salts are treated with ammonia, the major product and, under many conditions, the only product is the 5-substituted isothiazole. Of the four possible mechanisms for these reactions, an addition-elimination mechanism has been shown
[2+2] Cycloaddition Reactions of Isothiazoles Intramolecular Nucleophilic Attack On Isothiazolium Salts Preparation of New β-Lactam Systems Based on Isothiazole Nucleus
作者:Mohamed E. Hassan
DOI:10.1002/bscb.19850940213
日期:——
Abstract[2+2] cycloaddition reactions of isothiazoles with diphenyl ketene afford new fused β‐lactam systems. The intramolecular nucleophilic attack of carbanions on isothiazolium salts is found to take place on the ring sulphur atom. 2‐H‐2‐benzoyl‐1, 3‐thiazines were prepared and allowed to react with diphenyl ketene, or with acid chloride in the presence of a tertiary amine, to afford the corresponding β‐lactams.
US7655688B2
申请人:——
公开号:US7655688B2
公开(公告)日:2010-02-02
Access to 4-substituted isothiazoles through three-component cascade annulation and their application in C–H activation
作者:Guoling Huang、Jian Li、Xiaoliang Ji、Lu Chen、Qiang Liu、Xiuwen Chen、Yubing Huang、Yibiao Li
DOI:10.1039/d0cc01100b
日期:——
The use of potassium ethyl xanthate (EtOCS2k) as a sulfur atom donor enabled the transition-metal-free [3 + 1 + 1] cascadeannulation 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