A three‐component transition‐metal‐free aerobic method for the generation of 1,4‐benzothiazines is reported herein. The KI/DMSO/O₂ system was found to be effective for the oxidative cyclization/coupling of 2‐aminobenzenethiols, anilines, and methylketones. Hence, various structurally important imino 1,4‐benzothiazines were assembled with broad functional group tolerance. Mechanistic studies revealed an initial oxidation of ketone α C−H bonds by the KI/DMSO/O₂ oxidative system.

中文翻译：

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通过KI / DMSO / O2介导的三组分氧化环化/偶联合成1,4-苯并噻嗪

本文报道了一种用于生成1,4-苯并噻嗪的三组分无过渡金属好氧方法。发现KI / DMSO / O ₂系统对于2-氨基苯硫醇，苯胺和甲基酮的氧化环化/偶联有效。因此，组装了具有重要官能团耐受性的各种结构上重要的亚氨基1,4-苯并噻嗪。机理研究表明，KI / DMSO / O ₂氧化体系使酮αC-H键初步氧化。