Wannenmacher N, Pfeffer C, Frey W, Peters R. Enantioenriched γ-Aminoalcohols, β-Amino Acids, β-Lactams, and Azetidines Featuring Tetrasubstituted Fluorinated Stereocenters via Palladacycle-Catalyzed Asymmetric Fluorination of Isoxazolinones.
J Org Chem 2021;
87:670-682. [PMID:
34890190 DOI:
10.1021/acs.joc.1c02640]
[Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Enantiopure fluorine containing β-amino acids are of large biological and pharmaceutical interest. Strategies to prepare β-amino acid derivatives possessing a F-containing tetrasubstituted stereocenter at the α-C atom in a catalytic asymmetric sense are rare, in particular using an enantioselective electrophilic C-F bond formation. In the present study, a highly enantioselective palladacycle-catalyzed fluorination of isoxazolinones was developed. It is demonstrated that isoxazolinones are useful precursors toward enantiopure β-amino acid derivatives by diastereo- and chemoselective reduction. The formed γ-aminoalcohols served as valuable precursors toward β-amino acids, β-amino acid esters, and β-lactams, all featuring tetrasubstituted fluorinated stereocenters. In addition, by this work, enantioenriched fluorinated azetidines were accessible for the first time.
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