Switching the reaction pathways of electrochemically generated β-haloalkoxysulfonium ions – synthesis of halohydrins and epoxides

• Akihiro Shimizu,
• Ryutaro Hayashi,
• Yosuke Ashikari,
• Toshiki Nokami and
• Jun-ichi Yoshida

Beilstein J. Org. Chem. 2015, 11, 242–248, doi:10.3762/bjoc.11.27

• . Keywords: DMSO; electrosynthesis; epoxides; halohydrins; halogen cations; Introduction Alkene difunctionalization through three-membered ring halonium ion intermediates [1] is an important transformation in organic synthesis. Usually the halonium ions such as bromonium or iodonium ions are generated by

• the reaction of alkenes with Br2 and I2 [2]. However, the most straightforward method is the reaction of alkenes with halogen cations such as Br+ and I+. The I+ cation pool exists as reported by Filimonov et al. [3], although the used solvent is concentrated sulfuric acid which is therefore not

• compatible with most organic compounds. Electrochemical oxidation [4][5][6][7][8][9][10][11] is a potent technique to generate and accumulate highly reactive cationic species in solution (the “cation pool” method) [12][13][14][15][16][17]. Although halogen cations are too unstable to accumulate in solution