Selective C(sp<sup>3</sup>)–S Bond Cleavage of Thioethers to Build Up Unsymmetrical Disulfides
Ke Yang, Yanqi Luo, Qingyue Hu, Mengjie Song, Junxiang Liu, Zhengyi Li, Bijin Li, Xiaoqiang Sun
Abstract
The selective C(sp 3 )–S bond cleavage of thioethers was first developed to prepare unsymmetrical disulfides by using electrophilic halogenation reagents. In this strategy, NBS ( N -bromosuccinimide) achieves selective furfuryl C(sp 3 )–S bond cleavage of furfuryl alkylthioethers at room temperature. Meanwhile, NFSI ( N -fluorobenzenesulfonimide) enables selective methyl C(sp 3 )–S bond cleavage of aryl and alkyl methylthioethers at an elevated temperature. Notably, the substrate scope investigation indicates that the order of selectivity of the C–S bond cleavage is furfuryl C(sp 3 )–S > benzyl C(sp 3 )–S > alkyl C(sp 3 )–S > C(sp 2 )–S bond. Moreover, this practical and operationally simple strategy also provides an important complementary way to access various unsymmetrical disulfides with excellent functional group tolerances and moderate to good yields.