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Isothiourea-Catalyzed Enantioselective α-Alkylation of Esters via 1,6-Conjugate Addition to para-Quinone Methides.

ABSTRACT: The isothiourea-catalyzed enantioselective 1,6-conjugate addition of para-nitrophenyl esters to 2,6-disubstituted para-quinone methides is reported. para-Nitrophenoxide, generated in situ from initial N-acylation of the isothiourea by the para-nitrophenyl ester, is proposed to facilitate catalyst turnover in this transformation. A range of para-nitrophenyl ester products can be isolated, or derivatized in situ by addition of benzylamine to give amides at up to 99% yield. Although low diastereocontrol is observed, the diastereoisomeric ester products are separable and formed with high enantiocontrol (up to 94:6 er).

SUBMITTER: Arokianathar JN

PROVIDER: S-EPMC8588318 | biostudies-literature | 2021 Oct

REPOSITORIES: biostudies-literature

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Isothiourea-Catalyzed Enantioselective α-Alkylation of Esters via 1,6-Conjugate Addition to para-Quinone Methides.

Arokianathar Jude N JN Hartley Will C WC McLaughlin Calum C Greenhalgh Mark D MD Stead Darren D Ng Sean S Slawin Alexandra M Z AMZ Smith Andrew D AD

Molecules (Basel, Switzerland) 20211020 21

The isothiourea-catalyzed enantioselective 1,6-conjugate addition of para-nitrophenyl esters to 2,6-disubstituted para-quinone methides is reported. para-Nitrophenoxide, generated in situ from initial N-acylation of the isothiourea by the para-nitrophenyl ester, is proposed to facilitate catalyst turnover in this transformation. A range of para-nitrophenyl ester products can be isolated, or derivatized in situ by addition of benzylamine to give amides at ...[more]

PMID: 34770741

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