Catalytic\nEnantioselective Hydrogen Atom Abstraction\nEnables the Asymmetric Oxidation of <i>Meso</i> Diols

Desymmetrization\nof <i>meso</i> diols is an important\nstrategy for the synthesis of chiral oxygen-containing building blocks.\nOxidative desymmetrization is an important subclass, but existing\nmethods are often constrained by the need for activated alcohol substrates.\nWe disclose a conceptually distinct strategy toward oxidative diol\ndesymmetrization that is enabled by catalytic enantioselective hydrogen\natom abstraction. Following single electron oxidation of a cinchona\nalkaloid-derived catalyst, enantiodetermining hydrogen atom abstraction\ngenerates a desymmetrized ketyl radical intermediate which reacts\nwith either DIAD or O<sub>2</sub> before <i>in situ</i> elimination\nto form valuable hydroxyketone products. A range of cyclic and acyclic <i>meso</i> diols are competent, defining the absolute configuration\nof up to four stereocenters in a single operation. As well as providing\nrapid access to complex hydroxyketones, this work emphasizes the broad\nsynthetic potential of harnessing hydrogen atom abstraction in an\nenantioselective manner.