Rh‐Catalyzed Carboxylates Directed C–H Activation for the Synthesis of <i>ortho</i>‐Carboxylic 2‐Arylethenesulfonyl Fluorides: Access to Unique Electrophiles for SuFEx Click Chemistry

Abstract

The first Rh III ‐catalyzed activation of ortho ‐C–H bonds of arylcarboxylic esters for monoselective coupling with ethenesulfonyl fluoride (ESF) was developed. This protocol provides a convenient access to a class of otherwise difficult to access 2‐arylethenesulfonyl fluorides possessing ortho ‐carboxylic esters functionality. The synthesized 25 examples in up to 99 % isolated yields of 2‐arylethenesulfonyl fluorides bearing versatile carboxylic groups make this method remarkably applicable in developing biologically and pharmacologically active ethenesulfonyl fluorides, which are potential covalent drug candidates.