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

• ions generated by the reaction of electrogenerated Br+ and I+ ions stabilized by dimethyl sulfoxide (DMSO) reacted with sodium hydroxide and sodium methoxide to give the corresponding halohydrins and epoxides, respectively, whereas the treatment with triethylamine gave α-halocarbonyl compounds

• . 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

• expanding the utility of the present method. The treatment of β-haloalkoxysulfonium ions 3-X with sodium hydroxide gave the corresponding halohydrins 5-X, while the treatment with sodium methoxide gave epoxides 6 (Scheme 1). Results and Discussion Reactions of β-bromoalkoxysulfonium ions generated from (Z

Organocatalyzed enantioselective desymmetrization of aziridines and epoxides

• Ping-An Wang

Beilstein J. Org. Chem. 2013, 9, 1677–1695, doi:10.3762/bjoc.9.192

• 1.1 equiv of freshly distilled SiCl4 by using 10 mol % of HMPA as a catalyst in CH2Cl2 at −78 °C to afford the corresponding trans-vicinal halohydrins in high yields (up to 96%). This exciting discovery provides an opportunity to enantioselectively desymmetrize meso-epoxides by chiral phosphoramides

Alkenes from β-lithiooxyphosphonium ylides generated by trapping α-lithiated terminal epoxides with triphenylphosphine

• David. M. Hodgson and
• Rosanne S. D. Persaud

Beilstein J. Org. Chem. 2012, 8, 1896–1900, doi:10.3762/bjoc.8.219

• be generated by double deprotonation of β-hydroxy primary phosphonium salts [10][11][12][13][14][15][16][17][18][19], where the latter are obtained from Ph3P and 1,2-halohydrins [10][11][12][13][14][15][16][19] or (in the presence of acid) from terminal epoxides [17][18]. In seeking a more concise