Premium
Elemental Sulfur‐Promoted [2+3+1] Annulation for Synthesis of Functionalized Thiochromeno[2,3‐ b ]indoles from Indole Derivatives
Author(s) -
Liu Jianming,
Wang Zhixian,
Wang Ke,
Liu Dong,
Yang Yan,
Fan Junjun,
Zhuo Kelei,
Yue Yuanyuan
Publication year - 2020
Publication title -
asian journal of organic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.846
H-Index - 44
eISSN - 2193-5815
pISSN - 2193-5807
DOI - 10.1002/ajoc.202000159
Subject(s) - chemistry , indole test , annulation , sulfur , nucleophile , intermolecular force , combinatorial chemistry , aldehyde , cleavage (geology) , organic chemistry , stereochemistry , catalysis , molecule , geotechnical engineering , fracture (geology) , engineering
An intermolecular [2+3+1] annulation between indole and 2‐bromobenzylaldehyde derivatives was successfully achieved by utilizing elemental sulfur as the promoter and coupling partner. This direct and operationally simple procedure provided a rapid and reliable approach to synthesize functionalized thiochromeno[2,3‐ b ]indoles. Preliminary mechanistic studies indicated that elemental sulfur enhanced the nucleophilicity of the 3‐position of indole to attack an aldehyde group, and C−H cleavage of indole was not involved in the rate‐determining step.