Regio- and Stereoselective β-Sulfonylamination of Alkynes via Photosensitized Bifunctional N–S Bond Homolysis

Abstract

Nitrogen central radicals (NCRs) are versatile synthetic intermediates for creating functional nitrogen-containing molecules. Herein, a photosensitized β-sulfonylamination of terminal alkynes as well as acetylene has been established by employing N-sulfonyl heteroaromatics as bifunctional reagents (BFRs) to efficiently deliver versatile (E)-β-sulfonylvinylamines with excellent regio-and stereoselectivities. Mechanistic studies suggest a base-accelerated energy transfer (EnT) photocatalysis involving aromatic NCR formation, radical addition to alkynes, and sulfonylation processes.β-Sulfonylvinylamines are the most valuable structural backbones of many drugs and bioactive compounds (Figure 1a). 1Traditional synthetic β-sulfonylvinylamines from simple substrates usually undergo multiple steps and require harsh conditions such as high temperature and strong oxidants as well as transition-metal catalysts. 2 Therefore, it remains important to explore efficient protocols to build such skeletons by the convenient transformation of readily available starting materials.