# Copper(I)-Photocatalyzed Addition of Trichloromethanesulfenyl Chloride to Olefinic Compounds

## TL;DR

This paper introduces a new copper-based photocatalytic method to add a specific chemical group to olefins, creating useful compounds efficiently.

## Contribution

A novel photocatalytic method using Cu(I) and trichloromethanesulfenyl chloride for olefin difunctionalization is developed.

## Key findings

- Trichloromethanesulfenyl chloride adds to various olefins under Cu(I) photocatalytic conditions.
- The reaction produces α-chloro trichloromethylthioethers in good yields using 1 mol% catalyst.
- Mechanistic studies support a radical chain mechanism for the transformation.

## Abstract

Atom transfer radical addition (ATRA) reactions are essential transformations in organic synthetic chemistry that enable the atom-economic difunctionalization of abundant olefin feedstocks. In this way, a rich chemical space can be opened up by well-planned combinations of simple starting materials. To build an efficient photocatalytic transformation, the reactivity of trichloromethanesulfenyl chloride toward alkenes and alkynes was investigated under photocatalytic Cu(I) reaction conditions. In this study, we found that trichloromethanesulfenyl chloride can be added to a series of olefins (such as styrenes and electron-rich and -poor olefins) in the presence of 1 mol% [Cu(dmp)2]BF4 photocatalyst and blue LED irradiation, producing α-chloro trichloromethylthioethers in good yields. Experimental and theoretical (DFT) mechanistic studies are consistent with the proposed radical chain mechanism of transformation. This study may serve as a valuable reference for the development of new coupling reactions that are economical and highly efficient processes.