Radical Cyclization of Arenesulfonyl Chlorides and Alkynes: A Rapid Access to π-Conjugated Benzothiophenes
作者:Danyang Wan、Yudong Yang、Xingyan Liu、Mingliang Li、Siling Zhao、Jingsong You
DOI:10.1002/ejoc.201501439
日期:2016.1
A metal-free radicalcyclization of arenesulfonylchlorides with alkynes has been developed, which provides a rapid and practical access to a variety of π-conjugated benzothiophenes with a broad reactive functional group tolerance. Furthermore, dialkynyl compounds could also undergo this transformation to give extended π-systems in good yields.
A benzo[b]thiophene synthesis by Rh‐catalyzedthree‐component coupling reaction of arylboronic acids, alkynes, and elemental sulfur (S8) is developed. A notable feature of this protocol is that the thienannulation (thiophene annulation) proceeds with high regioselectivity via the sequential alkyne insertion, C−H activation, and then sulfur atom transfer to the metallacycle intermediate. In a similar
开发了通过Rh催化的芳基硼酸,炔烃和元素硫(S 8)的三组分偶联反应合成苯并[ b ]噻吩。该协议的一个显着特征是,噻吩环化(噻吩环化)通过顺序的炔烃插入,CH活化以及随后的硫原子转移至金属环中间体而以高区域选择性进行。可以类似的方式,由母体联芳基硼酸和S 8合成二苯并噻吩。