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Catalytic enantioselective radical coupling of activated ketones with N-aryl glycines.

ABSTRACT: Asymmetric H-bonding catalysis as a viable strategy for enantioselective radical coupling of ketones is demonstrated. With a visible-light-mediated dual catalytic system involving a dicyanopyrazine-derived chromophore (DPZ) photosensitizer and a chiral phosphoric acid (CPA), N-aryl glycines with a variety of 1,2-diketones and isatins underwent a redox-neutral radical coupling process and furnished two series of valuable chiral 1,2-amino tertiary alcohols in high yields with good to excellent enantioselectivities (up to 97% ee). In this catalysis platform, the formation of neutral radical intermediates between ketyl and H-bonding catalyst CPA is responsible for presenting stereocontrolling factors. Its success in this work should provide inspiration for expansion to other readily accessible ketones to react with various radical species, thus leading to a productive approach to access chiral tertiary alcohol derivatives.

SUBMITTER: Liu Y

PROVIDER: S-EPMC6238713 | biostudies-literature | 2018 Nov

REPOSITORIES: biostudies-literature

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Catalytic enantioselective radical coupling of activated ketones with <i>N</i>-aryl glycines.

Liu Yang Y Liu Xiangyuan X Li Jiangtao J Zhao Xiaowei X Qiao Baokun B Jiang Zhiyong Z

Chemical science 20180827 42

Asymmetric H-bonding catalysis as a viable strategy for enantioselective radical coupling of ketones is demonstrated. With a visible-light-mediated dual catalytic system involving a dicyanopyrazine-derived chromophore (DPZ) photosensitizer and a chiral phosphoric acid (CPA), <i>N</i>-aryl glycines with a variety of 1,2-diketones and isatins underwent a redox-neutral radical coupling process and furnished two series of valuable chiral 1,2-amino tertiary alcohols in high yields with good to excell ...[more]

PMID: 30542558

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