Gold(I)-Catalyzed 2-Deoxy-β-glycosylation via 1,2-Alkyl/Arylthio Migration: Synthesis of Velutinoside A Pentasaccharide.
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| Main Authors: | , , , , , , , , , |
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| Format: | Artículo científico |
| Language: | en |
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Journal of the American Chemical Society
2025
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| author | Wang, Xianyang Ding, Han Guo, Aoxin Song, Xiaofei Wang, Peng Song, Ni Yu, Biao Xu, Peng Liu, Xue-Wei Li, Ming |
| author_facet | Wang, Xianyang Ding, Han Guo, Aoxin Song, Xiaofei Wang, Peng Song, Ni Yu, Biao Xu, Peng Liu, Xue-Wei Li, Ming Wang, Xianyang Ding, Han Guo, Aoxin Song, Xiaofei Wang, Peng Song, Ni Yu, Biao Xu, Peng Liu, Xue-Wei Li, Ming |
| collection | PubMed - marine biology |
| contents | Gold(I)-Catalyzed 2-Deoxy-β-glycosylation via 1,2-Alkyl/Arylthio Migration: Synthesis of Velutinoside A Pentasaccharide. Wang, Xianyang Ding, Han Guo, Aoxin Song, Xiaofei Wang, Peng Song, Ni Yu, Biao Xu, Peng Liu, Xue-Wei Li, Ming 2-Deoxy-β-glycosides are essential components of natural products and pharmaceuticals; however, the corresponding 2-deoxy-β-glycosidic bonds are challenging to chemically construct. Herein, we describe an efficient catalytic protocol for synthesizing 2-deoxy-β-glycosides via either IPrAuNTf-catalyzed activation of a unique 1,2--positioned C2--propargyl xanthate (OSPX) leaving group or (PhO)PAuNTf-catalyzed activation of a 1,2--C2--alkynylbenzoate (OABz) substituent of the corresponding thioglycosides. These activation processes trigger 1,2-alkyl/arylthio-migration glycosylation, enabling the synthesis of structurally diverse 2-deoxy-β-glycosides under mild reaction conditions. The power of this strategy is demonstrated by the first synthesis of the pentasaccharide chain corresponding to velutinoside A, which features gold(I)-catalyzed construction of four successive β-l-oleandrosidic bonds in both a convergent and a one-pot glycosylation manner. Mechanistic studies, including control experiments and deuterium-labeling experiments, emphasize the crucial role of the OSPX and the involvement of the gold(I)-activated C≡C triple bond during the glycosylation process. The low-temperature NMR experiments unveiled a unique dual-coordination pattern of the gold(I) catalyst to the thiocarbonyl group and the alkynyl group of the OSPX, initiating a 5--dig cyclization process. Furthermore, density functional theory (DFT) simulations reveal the ligand-induced match-mismatch effect between leaving groups OSPX and OABz and gold catalysts IPrAuNTf and (PhO)PAuNTf. The DFT simulations also suggest that the formation of 2-deoxy-β-glycosidic bonds occurs via the bottom-face attack of the acceptor to the oxocarbenium intermediate, which adopts a half-chair conformation, leading to an energetically favored, -conformed intermediate that is stabilized by a hydrogen bonding interaction. |
| format | Artículo científico |
| id | pubmed_39869845 |
| institution | PubMed |
| language | en |
| publishDate | 2025 |
| publisher | Journal of the American Chemical Society |
| record_format | pubmed |
| spellingShingle | Gold(I)-Catalyzed 2-Deoxy-β-glycosylation via 1,2-Alkyl/Arylthio Migration: Synthesis of Velutinoside A Pentasaccharide. Wang, Xianyang Ding, Han Guo, Aoxin Song, Xiaofei Wang, Peng Song, Ni Yu, Biao Xu, Peng Liu, Xue-Wei Li, Ming Gold(I)-Catalyzed 2-Deoxy-β-glycosylation via 1,2-Alkyl/Arylthio Migration: Synthesis of Velutinoside A Pentasaccharide. Wang, Xianyang Ding, Han Guo, Aoxin Song, Xiaofei Wang, Peng Song, Ni Yu, Biao Xu, Peng Liu, Xue-Wei Li, Ming 2-Deoxy-β-glycosides are essential components of natural products and pharmaceuticals; however, the corresponding 2-deoxy-β-glycosidic bonds are challenging to chemically construct. Herein, we describe an efficient catalytic protocol for synthesizing 2-deoxy-β-glycosides via either IPrAuNTf-catalyzed activation of a unique 1,2--positioned C2--propargyl xanthate (OSPX) leaving group or (PhO)PAuNTf-catalyzed activation of a 1,2--C2--alkynylbenzoate (OABz) substituent of the corresponding thioglycosides. These activation processes trigger 1,2-alkyl/arylthio-migration glycosylation, enabling the synthesis of structurally diverse 2-deoxy-β-glycosides under mild reaction conditions. The power of this strategy is demonstrated by the first synthesis of the pentasaccharide chain corresponding to velutinoside A, which features gold(I)-catalyzed construction of four successive β-l-oleandrosidic bonds in both a convergent and a one-pot glycosylation manner. Mechanistic studies, including control experiments and deuterium-labeling experiments, emphasize the crucial role of the OSPX and the involvement of the gold(I)-activated C≡C triple bond during the glycosylation process. The low-temperature NMR experiments unveiled a unique dual-coordination pattern of the gold(I) catalyst to the thiocarbonyl group and the alkynyl group of the OSPX, initiating a 5--dig cyclization process. Furthermore, density functional theory (DFT) simulations reveal the ligand-induced match-mismatch effect between leaving groups OSPX and OABz and gold catalysts IPrAuNTf and (PhO)PAuNTf. The DFT simulations also suggest that the formation of 2-deoxy-β-glycosidic bonds occurs via the bottom-face attack of the acceptor to the oxocarbenium intermediate, which adopts a half-chair conformation, leading to an energetically favored, -conformed intermediate that is stabilized by a hydrogen bonding interaction. |
| title | Gold(I)-Catalyzed 2-Deoxy-β-glycosylation via 1,2-Alkyl/Arylthio Migration: Synthesis of Velutinoside A Pentasaccharide. |
| url | https://pubmed.ncbi.nlm.nih.gov/39869845/ |