Nickel-Catalyzed [5+2] Cycloaddition of 10π-Electron Aromatic Benzothiophenes with Alkynes To Form Thermally Metastable 12π-Electron Nonaromatic Benzothiepines

The nickel-catalyzed formal [5+2] cycloaddition of five-membered benzothiophenes and alkynes giving seven-membered benzothiepines via unprecedented dearomatization is reported. The reaction involves the carbothiolation of alkynes with sulfur-containing aromatic heterocycles affording sulfur-containi...

Full description

Saved in:
Bibliographic Details
Published in:Journal of the American Chemical Society 2019-08, Vol.141 (32), p.12541-12544
Main Authors: Inami, Tasuku, Takahashi, Toshifumi, Kurahashi, Takuya, Matsubara, Seijiro
Format: Article
Language:English
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:The nickel-catalyzed formal [5+2] cycloaddition of five-membered benzothiophenes and alkynes giving seven-membered benzothiepines via unprecedented dearomatization is reported. The reaction involves the carbothiolation of alkynes with sulfur-containing aromatic heterocycles affording sulfur-containing heterocyclic compounds via ring expansion. As a result, this method facilitates divergent access to thermally metastable benzothiepines. The structure of the thianickelacycle intermediate, which is formed via oxidative addition of the C–S bond in benzothiophenes to nickel(0), was confirmed by in situ X-ray absorption fine structure spectroscopy and density functional theory calculation.
ISSN:0002-7863
1520-5126
DOI:10.1021/jacs.9b07948