Asymmetric Oxidation of Enol Derivatives to α-Alkoxy Carbonyls Using Iminium Salt Catalysts: A Synthetic and Computational Study

Bulman Page, Philip C., Almutairi, Saud M., Chan, Yohan, Stephenson, G Richard, Gama, Yannick, Goodyear, Ross L., Douteau, Alice, Allin, Steven Mark and Jones, Garth A. (2019) Asymmetric Oxidation of Enol Derivatives to α-Alkoxy Carbonyls Using Iminium Salt Catalysts: A Synthetic and Computational Study. The Journal of Organic Chemistry, 84 (2). 544–559. ISSN 0022-3263

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    Abstract

    We report herein the first examples of asymmetric oxidation of enol ether and ester substrates using iminium salt organocatalysis, affording moderate to excellent enantioselectivities of up to 98% ee for tetralone-derived substrates in the α-hydroxyketone products. A comprehensive density functional theory study was undertaken to interpret the competing diastereoisomeric transition states in this example in order to identify the origins of enantioselectivity. The calculations gave good agreement with the experimental results, predicting 81% ee in favour of the (R)-enantiomer. Just one of the 30 characterized transition states dominates the enantioselectivity, which is attributed to the adoption of an orientation relative to stereochemical features of the chiral controlling element that places the smallest substituent on the alkene (a hydrogen atom) in the hindered position.

    Item Type: Article
    Faculty \ School: Faculty of Science > School of Chemistry
    Related URLs:
    Depositing User: LivePure Connector
    Date Deposited: 20 Dec 2018 16:31
    Last Modified: 23 Mar 2019 20:30
    URI: https://ueaeprints.uea.ac.uk/id/eprint/69415
    DOI: 10.1021/acs.joc.8b02354

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