Work

Closing the Carbon Loop: Continuous‐Flow Synthesis of N ‐Aroyl Sulfoximines via Electrochemical CO 2 Reduction

Year: 2026

Type: article

Abstract: Sulfoximines have emerged as versatile scaffolds in modern synthesis, medicinal chemistry, and catalysis due to their tunable electronic and steric properties. In particular, N ‐aroyl sulfoximines are valuable intermediates in amide coupling, CH functionalization, and heterocycle formation. However, conventional synthetic approaches often rely on stoichiometric activating reagents and harsh conditions, generating waste and limiting substrate scope. Herein, we report a sustainable continuous‐flow platform for the Pd‐catalyzed carbonylative N ‐aroylation of sulfoximines employing carbon monoxide (CO) as a C1 source under mild conditions. The system integrates a solid oxide electrolysis cell (SOEC) to generate dry CO from CO 2 on‐demand, enabling a safe, modular, and atom‐economical transformation. The process displayed broad substrate tolerance, accommodating electron‐rich, electron‐poor, and heteroaromatic aryl iodides to furnish N ‐aroyl sulfoximines in 50%–99% isolated yields within 40 min at 80°C and 6 bar. A heterogeneous Pd‐based catalyst, covalently immobilized on Merrifield resin, further enabled efficient flow operation with 96% conversion, facilitating the catalyst recovery. Finally, the adoption of Cyrene, a biomass‐derived solvent, afforded quantitative yields and demonstrated the process compatibility with green solvents. This work establishes a scalable, safe, and sustainable strategy for sulfoximine N ‐aroylation, integrating CO 2 valorization, continuous‐flow technology, and heterogeneous catalysis for modern carbonylation chemistry.

Source: ChemSusChem

DOI: 10.1002/cssc.70810