Metal-Free Synthesis of 2-Aminobenzothiazoles via Iodine-Catalyzed and Oxygen-Promoted Cascade Reactions of Isothiocyanatobenzenes with Amines
作者:Yuanshuang Xu、Bin Li、Xinying Zhang、Xuesen Fan
DOI:10.1021/acs.joc.7b01683
日期:2017.9.15
the cascade reactions of isothiocyanatobenzenes with primary or secondary amines by using iodine as a catalyst and oxygen as an oxidant is presented. Mechanistically, the formation of the title compounds involves the in situ formation of the required benzothiourea intermediate followed by its intramolecular cross dehydrogenative coupling of a C(sp2)–H bond and a S–H bond. To our knowledge, this should
本文提出了一种高效,可持续的合成方法,通过使用碘作为催化剂,氧气作为氧化剂,通过异硫氰酸根合苯与伯胺或仲胺的级联反应,合成2-氨基苯并噻唑。从机理上讲,标题化合物的形成涉及原位形成所需的苯并硫脲中间体,然后其分子内的C(sp 2)-H键和S-H键交叉脱氢偶联。就我们所知,这应该是第一个实例,其中使用碘作为催化剂,以分子氧作为氧化剂,以水为副产物,在无金属条件下由简单廉价的异硫氰酸酯和胺有效制备2-氨基苯并噻唑。与文献协议相比,该方法消除了使用邻卤取代的前体,昂贵的过渡金属催化剂和危险的氧化剂。