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Volumn 132, Issue 40, 2010, Pages 14288-14302

Nickel-catalyzed stereoselective glycosylation with C(2)- N-substituted benzylidene d-glucosamine and galactosamine trichloroacetimidates for the formation of 1,2-cis-2-amino glycosides. applications to the synthesis of heparin disaccharides, GPI anchor pseudodisaccharides, and α-GalNAc

Author keywords

[No Author keywords available]

Indexed keywords

ANOMERICS; BENZYLIDENE; COUPLING PROCESS; COUPLING PRODUCT; DISACCHARIDE DONOR; GALACTOSAMINE; GLUCOSAMINES; GLYCOCONJUGATES; GLYCOPEPTIDES; GLYCOSYL DONORS; HEPARIN DISACCHARIDE; HIGH YIELD; KEY COMPONENT; LIGAND COMPLEXES; LOW-YIELD; MECHANISTIC STUDIES; NOVEL METHODS; PROTECTING GROUP; REACTION TIME; REACTIVE SITE; STATE-OF-THE-ART METHODS; STEREO-SELECTIVE; TRICHLOROACETIMIDATES;

EID: 77957705226     PISSN: 00027863     EISSN: 15205126     Source Type: Journal    
DOI: 10.1021/ja106682m     Document Type: Article
Times cited : (103)

References (90)
  • 37
    • 77957710017 scopus 로고    scopus 로고
    • To determine if the α:β ratio of the coupling disaccharide 10 was thermodynamically or kinetically derived, the β-isomer of 10 was subjected to the similar nickel conditions. The β-isomer was not converted to the corresponding α-isomer. This result supports our hypothesis that the anomeric ratios of the 1,2- cis -2-amino glycoside products are kinetically derived and are not reflective of a thermodynamic product distribution arising from postcoupling anomeric epimerization
    • To determine if the α:β ratio of the coupling disaccharide 10 was thermodynamically or kinetically derived, the β-isomer of 10 was subjected to the similar nickel conditions. The β-isomer was not converted to the corresponding α-isomer. This result supports our hypothesis that the anomeric ratios of the 1,2- cis -2-amino glycoside products are kinetically derived and are not reflective of a thermodynamic product distribution arising from postcoupling anomeric epimerization.
  • 40
    • 77957698878 scopus 로고    scopus 로고
    • Donor 6 was prepared using the same route for the preparation of donor 5. See the Supporting Information for the preparation of donors 7 and 8
    • Donor 6 was prepared using the same route for the preparation of donor 5. See the Supporting Information for the preparation of donors 7 and 8.
  • 41
    • 77957700996 scopus 로고    scopus 로고
    • These results suggest that electron-withdrawing benzylidene donors accelerate the rate of reaction. To further confirm this hypothesis, we performed the control experiment with a 1:1 mixture of both electron-donating 4-methoxy-benzylidene d -glucosamine donor 5 and electron-withdrawing 4-fluoro-benzylidene d -glucosamine donor 7. In the presence of galactose 9 as the nucleophilic acceptor, a 3:1 ratio of disaccharide 12 to disaccharide 10 was observed under nickel conditions
    • These results suggest that electron-withdrawing benzylidene donors accelerate the rate of reaction. To further confirm this hypothesis, we performed the control experiment with a 1:1 mixture of both electron-donating 4-methoxy-benzylidene d -glucosamine donor 5 and electron-withdrawing 4-fluoro-benzylidene d -glucosamine donor 7. In the presence of galactose 9 as the nucleophilic acceptor, a 3:1 ratio of disaccharide 12 to disaccharide 10 was observed under nickel conditions.
  • 47
    • 77957699725 scopus 로고    scopus 로고
    • d -Galactosamine trichloroacetimidate donor 36 was prepared using the same route for the preparation of d -glucosamine donor 5
    • d -Galactosamine trichloroacetimidate donor 36 was prepared using the same route for the preparation of d -glucosamine donor 5.
  • 50
    • 77957692921 scopus 로고    scopus 로고
    • We only explored with the electron-withdrawing donors 7 and 8 because they would undergo glycosylation at a rate faster than that of 4-methoxy-benzylidene donor 5
    • We only explored with the electron-withdrawing donors 7 and 8 because they would undergo glycosylation at a rate faster than that of 4-methoxy-benzylidene donor 5.
  • 52
    • 77957719742 scopus 로고    scopus 로고
    • The procedures for preparation of disaccharide trichloroacetimidate donors 50 and 51 are described in the Supporting Information
    • The procedures for preparation of disaccharide trichloroacetimidate donors 50 and 51 are described in the Supporting Information.


* 이 정보는 Elsevier사의 SCOPUS DB에서 KISTI가 분석하여 추출한 것입니다.