Steric and Electronic Effect on C₂‐H Arylation of Sulfonamides

Abstract

The ambident nature of the electrophile generated in a reaction system controls the outcome of a reaction. Electrophilic nitrenium ion which is convertible to carbenium ion via resonance was in situ generated by the reactions of iodine(III)‐reagent PhI(OAc)2 and arylsulfonamides. The nucleophile added in the reaction controls the reaction for the regiospecific ortho C−H arylation or C2‐H arylation. The electron rich arenes react with carbenium ion (electrophiles) to undergo C−H arylation. Electron donating effect (+I or +R effect) of the substituents on sulfonamide stabilizes the carbenium ion to favor oxidative coupling reaction with nucleophiles. Overall, the feasibility of C2‐H arylation of the sulfonamides has been demonstrated by steric and electronic factor that facilitates C−H arylation of sulfonamides.