underwent the reaction to provide 3au in 95% yield. Notably, alkyl thiosulfonates performed smoothly to afford the corresponding products in high yields (3av-3ax). The configuration of 3ap was unambiguously determined by X-ray crystallography analysis. 19 To gain insight into the reaction mechanism, several control experiments were performed (Scheme 2). The addition of a radical scavenger TEMPO to the reaction has no influence on the formation of the product (eq. 1).