The development of new strategies for the direct catalytic functionalization of unprotected carbohydrates would be an enabling advance for glycoscience. Herein we report that the catalytic oxidation of unprotected carbohydrates can be carried out selectively with [(neocuproine)Pd(OAc)](2)(OTf)(2) (1) to generate the 3-ketoses. Catalytic aerobic oxidation can be carried out with Pd loadings as low as 1% in the presence of phenolic additives. Catalytic oxidation of a variety of unprotected pyranosides in acetonitrile or acetonitrile/water with Pd catalyst 1 with either oxygen or benzoquinone selectively generates the 3-ketoses. Minor amounts of the 4-ketoses are formed competitively, particularly in the case of pyranosides bearing axial substituents at C4 of the pyranoside. Catalytic oxidations can also be carried out in trifluorethanol, but for pyranosides bearing axial substituents at C2 or C4, selective oxidation to the 3-ketose is accompanied by epimerization to afford the equatorial 3-ketoses. Catalytic oxidation of unprotected hexafuranosides or sialic acid derivatives occurs selectively at the exocyclic diol or triol in trifluoroethanol to generate exocyclic hydroxyketones.
机构:
Acad Sinica, Genom Res Ctr, Taipei 115, TaiwanAcad Sinica, Genom Res Ctr, Taipei 115, Taiwan
Chang, Ken-Lien
;
Zulueta, Medel Manuel L.
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机构:
Acad Sinica, Genom Res Ctr, Taipei 115, Taiwan
Univ Philippines, Inst Chem, Quezon City 1101, PhilippinesAcad Sinica, Genom Res Ctr, Taipei 115, Taiwan
Zulueta, Medel Manuel L.
;
Lu, Xin-An
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机构:
Acad Sinica, Genom Res Ctr, Taipei 115, TaiwanAcad Sinica, Genom Res Ctr, Taipei 115, Taiwan
Lu, Xin-An
;
Zhong, Yong-Qing
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机构:
Acad Sinica, Genom Res Ctr, Taipei 115, TaiwanAcad Sinica, Genom Res Ctr, Taipei 115, Taiwan
Zhong, Yong-Qing
;
Hung, Shang-Cheng
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Acad Sinica, Genom Res Ctr, Taipei 115, Taiwan
Natl Chiao Tung Univ, Dept Appl Chem, Hsinchu 300, TaiwanAcad Sinica, Genom Res Ctr, Taipei 115, Taiwan
机构:
Univ Guelph, Guelph Waterloo Ctr Grad Work Chem, Dept Chem, Guelph, ON N1G 2W1, CanadaUniv Guelph, Guelph Waterloo Ctr Grad Work Chem, Dept Chem, Guelph, ON N1G 2W1, Canada
机构:
Acad Sinica, Genom Res Ctr, Taipei 115, TaiwanAcad Sinica, Genom Res Ctr, Taipei 115, Taiwan
Chang, Ken-Lien
;
Zulueta, Medel Manuel L.
论文数: 0引用数: 0
h-index: 0
机构:
Acad Sinica, Genom Res Ctr, Taipei 115, Taiwan
Univ Philippines, Inst Chem, Quezon City 1101, PhilippinesAcad Sinica, Genom Res Ctr, Taipei 115, Taiwan
Zulueta, Medel Manuel L.
;
Lu, Xin-An
论文数: 0引用数: 0
h-index: 0
机构:
Acad Sinica, Genom Res Ctr, Taipei 115, TaiwanAcad Sinica, Genom Res Ctr, Taipei 115, Taiwan
Lu, Xin-An
;
Zhong, Yong-Qing
论文数: 0引用数: 0
h-index: 0
机构:
Acad Sinica, Genom Res Ctr, Taipei 115, TaiwanAcad Sinica, Genom Res Ctr, Taipei 115, Taiwan
Zhong, Yong-Qing
;
Hung, Shang-Cheng
论文数: 0引用数: 0
h-index: 0
机构:
Acad Sinica, Genom Res Ctr, Taipei 115, Taiwan
Natl Chiao Tung Univ, Dept Appl Chem, Hsinchu 300, TaiwanAcad Sinica, Genom Res Ctr, Taipei 115, Taiwan
机构:
Univ Guelph, Guelph Waterloo Ctr Grad Work Chem, Dept Chem, Guelph, ON N1G 2W1, CanadaUniv Guelph, Guelph Waterloo Ctr Grad Work Chem, Dept Chem, Guelph, ON N1G 2W1, Canada