Electrochemical meta-C-H sulfonylation of pyridines with nucleophilic sulfinates

Nat Commun. 2024 Aug 28;15(1):7428. doi: 10.1038/s41467-024-50644-y.

Abstract

Considering the indispensable significance and utilities of meta-substituted pyridines in medicinal, chemical as well as materials science, a direct meta-selective C-H functionalization of pyridines is of paramount importance, but such reactions remain limited and highly challenging. In general, established methods for meta C-H functionalization of pyridines rely on the utilization of tailored electrophilic reagents to realize the intrinsic polarity match. Herein, we report a complementary electrochemical methodology; diverse nucleophilic sulfinates allow meta-sulfonylation of pyridines through a redox-neutral dearomatization-rearomatization strategy by a tandem dearomative cycloaddition/hydrogen-evolution electrooxidative C-H sulfonation of the resulting oxazino-pyridines/acid-promoted rearomatization sequence. Besides, several salient features, including exclusive regiocontrol, remarkable substrate/functional group compatibility, scale-up potential, and facile late-stage modification, have been demonstrated, which further contributes to the practicality and adaptability of this approach.