Metal-Free and NBS-Mediated C(sp³)-S Bond Cleavage of Thioethers to Access Alkyl Bromides

A selective C(sp3)-S bond cleavage of thioethers mediated by NBS is developed. Various alkyl bromides have been obtained in good yields using N-aryl-3-(methylthio)propanamides and arylmethylene alkylthioethers. Mechanistic studies suggest that the formation of 3-bromo-N-arylpropanamides may involve sulfoxide intermediates, while the arylmethylene bromides are formed through direct bromination process mediated by NBS. The significance of this strategy lies in its pioneering use of NBS for C-S bond cleavage and subsequent bromination reaction.