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Isothiourea-Catalyzed Enantioselective Michael Addition of Malonates to α,β-Unsaturated Aryl Esters.

ABSTRACT: An enantioselective Michael addition of malonates to α,β-unsaturated para-nitrophenyl esters was achieved using the Lewis basic isothiourea HyperBTM, giving excellent levels of product enantioselectivity (up to >99:1 enantiomeric ratio) in good yields and with complete regioselectivity (>20:1 regioselectivity ratio) in the presence of alternative (phenyl ketone and ethyl ester) Michael acceptors. Density functional theory calculations indicate that N-acylation is rate-limiting. This constitutes a rare example of a highly enantioselective addition of simple, readily available malonates to α,β-unsaturated esters.

SUBMITTER: Wu J

PROVIDER: S-EPMC9278409 | biostudies-literature | 2022 Jun

REPOSITORIES: biostudies-literature

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Isothiourea-Catalyzed Enantioselective Michael Addition of Malonates to α,β-Unsaturated Aryl Esters.

Wu Jiufeng J Young Claire M CM Watts Amy A AA Slawin Alexandra M Z AMZ Boyce Gregory R GR Bühl Michael M Smith Andrew D AD

Organic letters 20220602 22

An enantioselective Michael addition of malonates to α,β-unsaturated <i>para</i>-nitrophenyl esters was achieved using the Lewis basic isothiourea HyperBTM, giving excellent levels of product enantioselectivity (up to >99:1 enantiomeric ratio) in good yields and with complete regioselectivity (>20:1 regioselectivity ratio) in the presence of alternative (phenyl ketone and ethyl ester) Michael acceptors. Density functional theory calculations indicate that N-acylation is rate-limiting. This const ...[more]

PMID: 35652512

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