One-pot α-glycosylation pathway via the generation in situ of α-glycopyranosyl imidates in N,N-dimethylformamide

Yuko Shingu, Akira Miyachi, Yoshiko Miura, Kazukiyo Kobayashi, Yoshihiro Nishida

Research output: Contribution to journalArticle

27 Citations (Scopus)

Abstract

Divergent pathways are disclosed in the activation of 2-O-benzyl-1-hydroxy sugars by a reagent combination of CBr4 and Ph3P, all of which afford one-pot α-glycosylation methods. When this reagent is used in CH2Cl2, the 1-hydroxy sugar is converted to the α-glycosyl bromide in a conventional way and leads to the one-pot α-glycosylation method based on a halide ion-catalytic mechanism. In either DMF or a mixture of DMF and CHCl3, however, alternative α-glycosyl species are generated. From the 1H and 13C NMR study of the products, as well as the reactions using Vilsmeier reagents [(CH3)2N+CHX]X- (X = Br and Cl), these were identified as cationic α-glycopyranosyl imidates having either Br- or Cl- counter ion. The cationic α-glycosyl imidate (Br-), derived specifically in the presence of DMF, is more reactive than the α-glycosyl bromide and thus is responsible for the accelerated one-pot α-glycosylation. The one-pot α-glycosylation methodology performed in DMF was assessed also with different types of acceptor substrates including tertiary alcohols and an anomeric mixture of 1-OH sugars.

Original languageEnglish
Pages (from-to)2236-2244
Number of pages9
JournalCarbohydrate Research
Volume340
Issue number14
DOIs
Publication statusPublished - Oct 17 2005
Externally publishedYes

Fingerprint

Imidoesters
Glycosylation
Dimethylformamide
Sugars
Bromides
Ions
Radiation counters
Chemical activation
Alcohols
Nuclear magnetic resonance
Substrates

All Science Journal Classification (ASJC) codes

  • Analytical Chemistry
  • Biochemistry
  • Organic Chemistry

Cite this

One-pot α-glycosylation pathway via the generation in situ of α-glycopyranosyl imidates in N,N-dimethylformamide. / Shingu, Yuko; Miyachi, Akira; Miura, Yoshiko; Kobayashi, Kazukiyo; Nishida, Yoshihiro.

In: Carbohydrate Research, Vol. 340, No. 14, 17.10.2005, p. 2236-2244.

Research output: Contribution to journalArticle

Shingu, Yuko ; Miyachi, Akira ; Miura, Yoshiko ; Kobayashi, Kazukiyo ; Nishida, Yoshihiro. / One-pot α-glycosylation pathway via the generation in situ of α-glycopyranosyl imidates in N,N-dimethylformamide. In: Carbohydrate Research. 2005 ; Vol. 340, No. 14. pp. 2236-2244.
@article{ab05222869044ef5812e5c37ec70ef51,
title = "One-pot α-glycosylation pathway via the generation in situ of α-glycopyranosyl imidates in N,N-dimethylformamide",
abstract = "Divergent pathways are disclosed in the activation of 2-O-benzyl-1-hydroxy sugars by a reagent combination of CBr4 and Ph3P, all of which afford one-pot α-glycosylation methods. When this reagent is used in CH2Cl2, the 1-hydroxy sugar is converted to the α-glycosyl bromide in a conventional way and leads to the one-pot α-glycosylation method based on a halide ion-catalytic mechanism. In either DMF or a mixture of DMF and CHCl3, however, alternative α-glycosyl species are generated. From the 1H and 13C NMR study of the products, as well as the reactions using Vilsmeier reagents [(CH3)2N+CHX]X- (X = Br and Cl), these were identified as cationic α-glycopyranosyl imidates having either Br- or Cl- counter ion. The cationic α-glycosyl imidate (Br-), derived specifically in the presence of DMF, is more reactive than the α-glycosyl bromide and thus is responsible for the accelerated one-pot α-glycosylation. The one-pot α-glycosylation methodology performed in DMF was assessed also with different types of acceptor substrates including tertiary alcohols and an anomeric mixture of 1-OH sugars.",
author = "Yuko Shingu and Akira Miyachi and Yoshiko Miura and Kazukiyo Kobayashi and Yoshihiro Nishida",
year = "2005",
month = "10",
day = "17",
doi = "10.1016/j.carres.2005.07.020",
language = "English",
volume = "340",
pages = "2236--2244",
journal = "Carbohydrate Research",
issn = "0008-6215",
publisher = "Elsevier BV",
number = "14",

}

TY - JOUR

T1 - One-pot α-glycosylation pathway via the generation in situ of α-glycopyranosyl imidates in N,N-dimethylformamide

AU - Shingu, Yuko

AU - Miyachi, Akira

AU - Miura, Yoshiko

AU - Kobayashi, Kazukiyo

AU - Nishida, Yoshihiro

PY - 2005/10/17

Y1 - 2005/10/17

N2 - Divergent pathways are disclosed in the activation of 2-O-benzyl-1-hydroxy sugars by a reagent combination of CBr4 and Ph3P, all of which afford one-pot α-glycosylation methods. When this reagent is used in CH2Cl2, the 1-hydroxy sugar is converted to the α-glycosyl bromide in a conventional way and leads to the one-pot α-glycosylation method based on a halide ion-catalytic mechanism. In either DMF or a mixture of DMF and CHCl3, however, alternative α-glycosyl species are generated. From the 1H and 13C NMR study of the products, as well as the reactions using Vilsmeier reagents [(CH3)2N+CHX]X- (X = Br and Cl), these were identified as cationic α-glycopyranosyl imidates having either Br- or Cl- counter ion. The cationic α-glycosyl imidate (Br-), derived specifically in the presence of DMF, is more reactive than the α-glycosyl bromide and thus is responsible for the accelerated one-pot α-glycosylation. The one-pot α-glycosylation methodology performed in DMF was assessed also with different types of acceptor substrates including tertiary alcohols and an anomeric mixture of 1-OH sugars.

AB - Divergent pathways are disclosed in the activation of 2-O-benzyl-1-hydroxy sugars by a reagent combination of CBr4 and Ph3P, all of which afford one-pot α-glycosylation methods. When this reagent is used in CH2Cl2, the 1-hydroxy sugar is converted to the α-glycosyl bromide in a conventional way and leads to the one-pot α-glycosylation method based on a halide ion-catalytic mechanism. In either DMF or a mixture of DMF and CHCl3, however, alternative α-glycosyl species are generated. From the 1H and 13C NMR study of the products, as well as the reactions using Vilsmeier reagents [(CH3)2N+CHX]X- (X = Br and Cl), these were identified as cationic α-glycopyranosyl imidates having either Br- or Cl- counter ion. The cationic α-glycosyl imidate (Br-), derived specifically in the presence of DMF, is more reactive than the α-glycosyl bromide and thus is responsible for the accelerated one-pot α-glycosylation. The one-pot α-glycosylation methodology performed in DMF was assessed also with different types of acceptor substrates including tertiary alcohols and an anomeric mixture of 1-OH sugars.

UR - http://www.scopus.com/inward/record.url?scp=24644484201&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=24644484201&partnerID=8YFLogxK

U2 - 10.1016/j.carres.2005.07.020

DO - 10.1016/j.carres.2005.07.020

M3 - Article

C2 - 16098494

AN - SCOPUS:24644484201

VL - 340

SP - 2236

EP - 2244

JO - Carbohydrate Research

JF - Carbohydrate Research

SN - 0008-6215

IS - 14

ER -