CH Functionalization of Enamides: Synthesis of β‐Amidovinyl Sulfones via Visible‐Light Photoredox Catalysis

Abstract

A mild, practical and environmentally friendly strategy to prepare b-amidovinyl sulfones has been developed based on the sulfonation of enamides or enecarbamates via visible-light photoredox catalysis. Direct C À H functionalizations of enamides or enecarbamates under the optimized conditions proceeded with a wide scope of substrates and remarkable selectivity to give functionalized vinyl sulfones with good to excellent yields.

Visible Light‐Mediated Metal‐Free Synthesis of Vinyl Sulfones from Aryl Sulfinates

“…In 2013, Yu et al. described a visible‐light photoredox‐catalyzed protocol for the synthesis of β‐amidovinyl sulfones from enamides with sulfonyl chlorides 14. They used [Ir(ppy) 2 (dtb‐bpy)]PF 6 and synthesized exclusively β‐amidovinyl sulfones with sulfonyl chlorides as sulfonylation reagents.…”

Visible Light‐Induced C−H Bond Functionalization: A Critical Review

“…Inspired by MacMillan's work, as well as their own research on visible light‐promoted C−H functionalization of enamides, Yu and co‐workers developed a similar strategy by using a readily accessible hydroxylamine derivative as an N‐radical precursor, which proved to be an efficient and broadly applicable visible‐light photoredox‐catalyzed direct C−H bond amination of various heteroarenes, including indoles, pyrroles, and furans (Scheme ).…”

Photocatalytic formation of carbon–sulfur bonds

“…The groups of Zhang and Yu reported two additional photoredox-catalyzed methods for the sulfonylation of olefins. In their first paper they applied enamides as olefins, which were sulfonylated to the respective β-amidovinyl sulfones under irradiation with visible light and [Ir(ppy) 2 (dtbbpy)]PF 6 as photocatalyst ( Scheme 52 ) [ 89 ]. The scope of this method includes cross-coupling of electron-rich, neutral and electron-deficient (hetero)aromaticsulfonyl chlorides and even alkylsulfonyl chlorides with (a) cyclic enamides, different N -vinyllactams and enecarbamates.…”