Enantioselective Sulfoxidation Catalyzed by a Bisguanidinium Diphosphatobisperoxotungstate Ion Pair
Xinyi Ye, Adhitya Mangala Putra Moeljadi, Kek Foo Chin, Prof. Dr. Hajime Hirao, Dr. Lili Zong and Prof. Dr. Choon‐Hong Tan
Angew. Chem. Int. Ed., 2016, 55, 7101 − 7105
Abstract: The first enantioselective tungstate‐catalyzed oxidation reaction is presented. High enantioselectivities were achieved for a variety of drug‐like phenyl and heterocyclic sulfides under mild conditions with H2O2, a cheap and environmentally friendly oxidant. Synthetic utility was demonstrated through the preparation of (S)‐Lansoprazole, a commercial proton‐pump inhibitor. The active ion‐pair catalyst was identified to be bisguanidinium diphosphatobisperoxotungstate using Raman spectroscopy and computational studies.