# Activation of gem-Dichloroacetamides and Epoxides Using Elemental Sulfur and Amines: A Route to Monothiooxalamides and α‑Ketothioamides

## TL;DR

This paper presents a metal-free method to create valuable chemical compounds using sulfur and amines, offering a sustainable and efficient approach for industrial applications.

## Contribution

A novel metal-free strategy for synthesizing monothiooxalamides and α-ketothioamides using elemental sulfur and amines.

## Key findings

- Monothiooxalamides were synthesized via C–S and C–N bond formation under ambient conditions.
- α-Ketothioamides were efficiently produced through regioselective epoxide ring-opening with S8 and amines.
- Monothiooxalamides showed high efficacy as ligands in Cu-catalyzed C–N cross-coupling reactions.

## Abstract

The selective activation of C–X bonds to generate
value-added
products via transition metal-free methodologies remains a formidable
challenge in modern synthetic chemistry. Herein, we report a metal-free
didechlorinative strategy for the construction of unsymmetrical monothiooxalamides
through C–S and C–N bond formation. This transformation
proceeds via a one-pot functionalization of gem-dichloroacetamides
with various amines and elemental sulfur (S8) under ambient
conditions in an open-air atmosphere, offering a sustainable and operationally
simple approach. Additionally, a regioselective epoxide ring-opening
approach was implemented using I2/DMSO, enabling the efficient
synthesis of α-ketothioamides through
the incorporation of S8 and diverse amine nucleophiles.
Furthermore, ligand studies revealed that monothiooxalamides exhibit
high efficacy as ligands in Cu-catalyzed C–N cross-coupling
reactions. The method’s synthetic utility was further demonstrated
through gram-scale synthesis and the preparation of natural product
derivatives and drug analogues, highlighting its potential for industrial
applications.