| Project/Area Number |
10440217
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| Research Category |
Grant-in-Aid for Scientific Research (B).
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
物質変換
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| Research Institution | Science University of Tokyo |
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Principal Investigator |
MUKAIYAMA Teruaki Science University of Tokyo, Faculty of Science, Professor, 理学部, 教授 (60016003)
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| Co-Investigator(Kenkyū-buntansha) |
SHIINA Isamu Science University of Tokyo, Faculty of Science, Lecturer, 理学部, 講師 (40246690)
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| Project Period (FY) |
1998 – 2000
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| Project Status |
Completed (Fiscal Year 2000)
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| Budget Amount *help |
¥11,500,000 (Direct Cost: ¥11,500,000)
Fiscal Year 2000: ¥3,900,000 (Direct Cost: ¥3,900,000)
Fiscal Year 1999: ¥3,800,000 (Direct Cost: ¥3,800,000)
Fiscal Year 1998: ¥3,800,000 (Direct Cost: ¥3,800,000)
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| Keywords | Glycosylation / Trisaccharides / One-pot sequential syntheses / Thioglycoside / Trityl tetrakis(pentafluorophenyl)borate / Trifluoromethanesulfonic acid / N-(Ethylthio)phthalimide / 連続的反応 / N-ヨ-ドコハク酸イミド / N-ブロモコハク酸イミド / ルイス酸 / 2-デオキシピラノシド / チオカルバモイル基 / ワンポット合成 |
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| Research Abstract |
Stereoselective glycosylation of 2-O-benzoyl-3,4,6-tri-O-benzyl-β-D-glucosyl fluoride with several glycosyl acceptors is successfully carried out by using a catalytic amount of trifluoromethanesulfonic acid (TfOH).
A catalytic and stereoselective glycosylation of several glycosyl acceptors with β-glycosyl fluoride is successfully performed by using a catalytic amount of trityl tetrakis(pentafluorophenyl)borate [TrB(C_6F_5)_4] or TfOH.When TrB(C_6F_5)_4 was used as a catalyst, the glycosylation proceeded smoothly to afford the glycosides in high yields with high β-stereselectivities in pivalonitrile-trifluoromethylbenzene (BTF) 1 : 5 mixed solvent. Further, the glycosylation reaction of armed-disarmed strategy with this catalyst was established. Similarly, TfOH, a strong protic acid, catalyzed glycosylation afforded the corresponding β-glycosides in good to excellent yields on treating β-glycosyl fluorides having 2-O-benzoyl group with various glycosyl acceptors including thioglycosides.
Glycosylation of the "armed" thioglycoside with various glycosyl acceptors is promoted by using a combination of stoichiometoric amount of N-(ethylthio)phthalimide (PhthNSEt) and catalytic amount of TrB(C_6F_5)_4, and is successfully applied to one-pot "armed-disarmed" sequential synthesis of trisaccharides.
Stereoselective glycosylation of several glycosyl acceptors with 2,3,4,6-tetra-O-benzyl-β-D-glucopyranosyl fluoride was successfully carried out in diethylether by using a catalytic amount of TfOH in the coexistence of molecular sieve 5Å (MS5Å) to afford predominantly the corresponding α-linked disaccharides in high yields, which was applied to one-pot sequential syntheses of trisaccharides.
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