Zheng-Yang Gu,^a   Jia-Jia Cao,^a   Shun-Yi Wang*^a （汪顺义）and  Shun-Jun Ji*^a （纪顺俊）

^aKey Laboratory of Organic Synthesis of Jiangsu Province, College of Chemistry, Chemical Engineering and Materials Science & Collaborative Innovation Center of Suzhou Nano Science and Technology, Soochow University

Chem. Sci., 2016,7, 4067-4072

An efficient and practical synthesis of benzothiazine by K₂S initiated sulfur insertion reaction with enaminones via electron catalysis is developed. This protocol provides a new, environment-friendly and simple strategy to construct benzothiazine derivatives via formation of two C–S bonds under transition metal-free, additive-free and oxidant-free conditions. K₂S not only provides the sulfur insertion source, but also ignites the reaction through the formation of a trisulfur radical anion and electrons in DMF.

链接：http://pubs.rsc.org/en/content/articlelanding/2016/sc/c6sc00240d#!divAbstract