# N‑Boryl Pyridyl Radical-Mediated Reductive Homocoupling of Arylsulfonyl Chlorides to Diaryl Disulfides

## TL;DR

A new method uses radicals to convert arylsulfonyl chlorides into diaryl disulfides efficiently.

## Contribution

A novel reductive homocoupling method using N-boryl pyridyl radicals is introduced for diaryl disulfide synthesis.

## Key findings

- Arylsulfonyl chlorides can be converted into symmetrical diaryl disulfides using a 4-cyanopyridine catalyst.
- The reaction proceeds via arylsulfonyl radicals and single-electron reductions mediated by N-boryl pyridyl radicals.
- The method allows for the synthesis of a variety of diaryl disulfides under mild conditions.

## Abstract

Arylsulfonyl chlorides were found to undergo 4-cyanopyridine-catalyzed,
bis­(pinacolato)­diboron-mediated reductive homocoupling to afford a
variety of symmetrical diaryl disulfides. Preliminary mechanistic
studies suggest that arylsulfonyl radicals are involved and that diaryl
disulfide formation likely proceeds through successive single-electron
reductions mediated by N-boryl pyridyl radicals.