From left: Prof. K Ohmatsu, Dr. Y. Ando, Prof. T Ooi (Nagoya University and CREST, Japan Science and Technology Agency, Nagoya, Japan)zoom
Catalytic Asymmetric α-Hydroxylation of 3-Substituted Oxindoles with Hydrogen Peroxide
Takashi Ooi presents the asymmetric α-hydroxylation of 3-substituted oxindoles with hydrogen peroxide.
In Situ Electrophilic Activation of Hydrogen Peroxide for Catalytic Asymmetric α-Hydroxylation of 3-Substituted Oxindoles: K. Ohmatsu, Y. Ando, T. Ooi
Synlett 2017, 28, DOI: 10.1055/s-0036-1558958
Conversion of hydrogen peroxide into an electrophilic hydroxylating agent by activation with an electrophile can be an ingenious way to achieve hydroxylation of nucleophilic reagents, such as enolates, especially if the transformation can be performed in a stereocontrolled manner. Recently, the group of Professor Takashi Ooi at Nagoya University (Japan) has reported the successful enantioselective conversion of oxindoles into α-hydroxy-oxindoles using H2O2 as the oxidant.
Synthesis of 3-substituted oxindoleszoom
Professor Ooi said: “The in situ activation of aqueous hydrogen peroxide with trichloroacetonitrile enables direct enantioselective transfer of the hydroxyl group to the α-position of oxindoles under catalysis with chiral 1,2,3-triazolium salts.”