Photoredox‐Catalyzed Sulfonaminoformyloxylation of Alkenes with N‐Aminopyridinium Salts and DMF

Abstract

A photoredox‐catalyzed three‐component sulfonoaminoformyloxylation reaction between alkenes, N‐aminopyridinium salts and DMF has been developed, which avoids the usage of erosive formic acid as the formyloxylation reagent. Besides DMF, alkyl and aryl carboxylic acids proved to be feasible nucleophiles to afford various β‐amino esters. The robustness of this method was further demonstrated by its applicability in the late‐stage modification of biological molecules. Control experiments suggested that a sulfonamidyl radical was involved in this reaction.

Direct Fluorosulfonamidation of (Hetero)arenes and Alkenes with Photoredox-Active Fluorosulfamoyl Radical Reagents

“…In continuation of our keen interest in exploring radical fluorosulfonylation methodology, − we aimed to design bench-stable and readily available radical reagents to facilitate fluorosulfonamidation reactions. Drawing inspiration from recent advances in the utilization of N-functionalized pyridinium salts as versatile reagents, − we successfully synthesized the required N -fluorosulfamoyl pyridium reagents (NFSAP- 1a ) in two steps from commercially available N -aminopyridium iodide and the structure of 1a was elucidated through X-ray single-crystal diffraction (CCDC: 2353363). We envisioned that N-centered fluorosulfamoyl radicals could be generated through the cleavage of weak N-heteroatom bonds tethered to redox-active scaffolds.…”