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Efficacy of Selenourea Organocatalysts in Asymmetric Michael Reactions under Standard and Solvent-Free Conditions.

ABSTRACT: By varying the steric and electronic surroundings of the hydrogen-bonding motif, the novel chiral Cinchona-alkaloid based selenoureas were developed. Acting as bifunctional catalysts, they were applied in the Michael reactions of dithiomalonate and nitrostyrene providing chiral adducts with up to 96% ee. The asymmetric Michael--hemiacetalization reaction of benzylidene pyruvate and dimedone, performed with the assistance of 5 mol% of selenoureas, furnished the product with up to 93% ee and excellent yields. The effectiveness of the new hydrogen-bond donors was also proved in solvent-free reactions under ball mill conditions, supporting the sustainability of the devised catalytic protocol.

SUBMITTER: Zielinska-Blajet M

PROVIDER: S-EPMC8658871 | biostudies-literature | 2021 Dec

REPOSITORIES: biostudies-literature

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Efficacy of Selenourea Organocatalysts in Asymmetric Michael Reactions under Standard and Solvent-Free Conditions.

Zielińska-Błajet Mariola M Mała Żaneta A ŻA Kowalczyk Rafał R

Molecules (Basel, Switzerland) 20211201 23

By varying the steric and electronic surroundings of the hydrogen-bonding motif, the novel chiral <i>Cinchona</i>-alkaloid based selenoureas were developed. Acting as bifunctional catalysts, they were applied in the Michael reactions of dithiomalonate and nitrostyrene providing chiral adducts with up to 96% ee. The asymmetric Michael--hemiacetalization reaction of benzylidene pyruvate and dimedone, performed with the assistance of 5 mol% of selenoureas, furnished the product with up to 93% ee an ...[more]

PMID: 34885885

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