Transition‐Metal‐Free Allylic Defluorination Cross‐Electrophile Coupling Employing Rongalite

Abstract

Comprehensive SummaryThe conversion of CF3‐alkenes to gem‐difluoroalkenes using reductive cross‐coupling strategy has received much attention in recent years, however, the use of green and readily available reducing salt to mediate these reactions remains to be explored. In this work, a concise construction of gem‐difluoroalkenes, which requires neither a catalyst nor a metal reducing agent, was established. Rongalite, a safe and inexpensive industrial product, was employed as both a radical initiator and reductant. This procedure was compatible with both linear and cyclic diaryliodonium salts, enabling a wide variety of substrates (>70 examples). The utility of this approach was demonstrated through gram‐scale synthesis and efficient late‐stage functionalizations of anti‐inflammatory drugs.

Synthesis of β,β-Dithioketones by Merging C–C and C–S Bond Cleavage in [1 + 1 + 1 + 1 + 1 + 1] Annulation

“…Based on the results of the control experiments and previous reports, − a possible reaction mechanism was proposed (Scheme ). First, 1b and 2 undergo nucleophilic substitution to obtain species I , which undergoes a second nucleophilic substitution with 2 to afford intermediate II .…”