Heteroarylation of Sulfenate Ions In Situ Generated from β-Sulfinyl Esters under Transition-Metal-Free Conditions

Heteroaryl sulfoxides are an integral part of several bioactive molecules and pharmaceuticals. We have described a transition-metal-free route for the direct sulfinylation of 2-halobenzothiazoles and 2-halobenzimidazoles using fi-sulfinyl esters as the source of the sulfenate ion in the presence of a Bronsted base such as LiOtBu, and the corresponding heteroaryl sulfoxides were isolated in yields of 30 to 94%. Moreover, we hypothesized a plausible concerted nucleophilic aromatic substitution (cSNAr) pathway for the direct incorporation of sulfinyl functionality into the 2-haloheteroarenes.

Automated summary

A transition-metal-free method for the direct synthesis of heteroaryl sulfoxides has been described. By using fi-sulfinyl esters as the source of the sulfenate ion and a Bronsted base catalyst, the desired heteroaryl sulfoxides were obtained in yields of 30 to 94%.