64694-21-9Relevant academic research and scientific papers
Tris(pentafluorophenyl)borane-promoted stereoselective glycosylation with glycosyl trichloroacetimidates under mild conditions
Mishra, Kunj Bihari,Singh, Adesh Kumar,Kandasamy, Jeyakumar
, p. 4204 - 4212 (2018/04/14)
Tris(pentafluorophenyl)borane-promoted stereoselective glycosylation with trichloroacetimidate glycosyl donors is described. The reactions proceed efficiently with a wide range of acceptors, from sugar to nonsugar, under mild conditions in the presence of
A 1,2-trans-Selective Glycosyl Donor Bearing Cyclic Protection at the C-2 and C-3 Hydroxy Groups
Yagami, Nahoko,Tamai, Hideki,Udagawa, Taro,Ueki, Akiharu,Konishi, Miku,Imamura, Akihiro,Ishida, Hideharu,Kiso, Makoto,Ando, Hiromune
supporting information, p. 4778 - 4785 (2017/09/07)
A new 1,2-trans-selective glycosylation reaction is described. Glucosyl donors protected cyclically at the C-2 and C-3 hydroxy groups as six- (butane diacetal), seven- (tetraisopropyldisiloxanylidene), or eight- (2,3-o-xylylene) membered fused rings were synthesized in a straightforward manner. The glycosylation reactions of the glucosyl donors with various acceptors mainly generated β-glycosides under conventional reaction conditions. The results show that the o-xylylene group is a suitable 1,2-trans-directing group from the points of view of stereoselectivity and chemical stability. A conformational study of the oxocarbenium ion of an o-xylylene-protected glucose derivative by NMR spectroscopy and computational simulation was carried out. The results imply that the oxocarbenium ion mainly adopts a 4H3 conformation owing to the rigid trans-fused ring at C-2 and C-3, while a noncyclically protected derivative might fluctuate between conformations. These results suggest that an eclipsing interaction between the pseudoequatorial xyloxy group at C-2 and the incoming nucleophile hampers 1,2-cis attack.
How the arming participating moieties can broaden the scope of chemoselective oligosaccharide synthesis by allowing the inverse armed-disarmed approach
Smoot, James T.,Demchenko, Alexei V.
experimental part, p. 8838 - 8850 (2009/04/05)
(Chemical Equation Presented) A new method for stereocontrolled glycosylation and chemoselective oligosaccharide synthesis has been developed. It has been determined that complete 1,2-trans selectivity can be achieved with the use of a 2-O-picolyl moiety,
Dichloro-cyanoacetimidates as glycosyl donors
Schmelzer, Uwe,Zhang, Zhaojun,Schmidt, Richard R.
, p. 223 - 238 (2008/02/12)
Transformation of 1-O-unprotected glucose and galactose derivatives (1a-d) into O-glycosyl dichloro-cyanoacetimidates (2a-d) was performed with dichloro-cyanoacetonitrile in the presence of DBU as base. Reaction with different acceptors (3a-d) under TMSOT
A new efficient glycosylation method employing glycosyl pentenoates and PhSeOTf
Choi, Tae Jin,Baek, Ju Yuel,Jeon, Heung Bae,Kim, Kwan Soo
, p. 9191 - 9194 (2007/10/03)
The PhSeOTf promoted glycosylations of various glycosyl acceptors with mannosyl pentenoates and glucosyl pentenoates as glycosyl donors afforded corresponding disaccharides in high yields. And the present glycosyl pentenoates/PhSeOTf method showed that th
Glycosyl disulfides: Novel glycosylating reagents with flexible aglycon alteration
Grayson, Elizabeth J.,Ward, Sarah J.,Hall, Alison L.,Rendle, Phillip M.,Gamblin, David P.,Batsanov, Andrei S.,Davis, Benjamin G.
, p. 9740 - 9754 (2007/10/03)
Glycosyl disulfides have been shown for the first time to be effective glycosyl donors. Glucosylation and galactosylation of a panel of representative alcohol acceptors allowed the formation of 28 simple glycosides, disaccharides, and glycoamino acids in yields of up to 90%. As well as providing a novel class of effective glycosyl donors, the ability to easily alter the nature of the aglycon and the ability to differently activate donors that differ only in their aglycon simply through altering conditions lends glycosyl disulfide donors to their use in latent-active reactivity tuning strategies.
Stereoselective O-glycosylation reactions using glycosyl donors with diphenylphosphinate and propane-1,3-diyl phosphate leaving groups
Vankayalapati, Hariprasad,Singh, Gurdial,Tranoy, Isabelle
, p. 1373 - 1381 (2007/10/03)
Glycosyl donors having a diphenylphosphinate and a propane-1,3-diyl phosphate leaving group were easily prepared by the addition of the anomeric hydroxyl group of 2,3,4,6-tetra-O-benzyl-α,β-D-glucopyranose to diphenylphosphinic and propane-1,3- diyldioxyphosphoryl chlorides. These glycosyl donors were selectively glycosylated with a number of primary and secondary oxygen nucleophiles in the presence of trimethylsilyl triflate (TMSOTf). The use of 1,3-diyl phosphate resulted in the stereoselective formation of β-O-linked glycosides.
A new, efficient glycosylation method for oligosaccharide synthesis under neutral conditions: Preparation and use of new DISAL donors
Petersen,Jensen
, p. 6268 - 6275 (2007/10/03)
Efficient, stereoselective glycosylation methods are required for the synthesis of complex oligosaccharides as tools in glycobiology. All glycosylation methods, which have found wide acceptance, rely on Lewis acid activation of glycosyl donors prior to glycosylation. Here, we present a new and efficient method for glycosylation under neutral or mildly basic conditions. Glycosides of methyl 2-hydroxy-3,5-dinitrobenzoate (DISAL) and its para regioisomer, methyl 4-hydroxy-3,5-dinitrobenzoate, were prepared by nucleophilic aromatic substitution. In a first demonstration of their potential as glycosyl donors, stereospecific glycosylation of methanol was achieved. In the glycosylation of more hindered alcohols, the β-donor proved more reactive, and α-glucosides were predominantly formed. Glycosylation of protected monosaccharides, with free 6-0H or 3-OH, proceeded smoothly in 1-methyl-2-pyrrolidinone (NMP) at 40-60 °C in the absence of Lewis acids and bases in good to excellent yields. Glycosylation of 3-OH gave the α-linked disaccharide only.
Glycosyl iodides are highly efficient donors under neutral conditions
Hadd, Michael J.,Gervay, Jacquelyn
, p. 61 - 69 (2007/10/03)
Glycosyl iodides have been prepared and subjected to glycosylation under neutral conditions. The reactions are highly efficient, giving α glycosides even with sterically demanding glycosyl acceptors. Glucosyl iodides react with allyl alcohol slowest and require refluxing conditions. Galactosyl iodides are intermediate in reactivity, providing the allyl glycoside in 3 h at room temperature, whereas glycosylation of fucosyl iodides occurs in less than 1 h under similar conditions. The scope and limitations of the reactions were demonstrated with a variety of acceptors, including an anomeric hydroxyl group, to give trehalose analogs. β-Selective glycosylation of glucosyl iodides, in the absence of C-2 participation, could be achieved by simply changing the solvent from benzene to acetonitrile. Copyright (C) 1999 Elsevier Science Ltd.
An extremely mild and stereocontrolled construction of 1,2-cis-α-glycosidic linkages via benzyl-protected glycopyranosyl diethyl phosphites
Tanaka, Hiroko,Sakamoto, Hiroki,Sano, Ai,Nakamura, Seiichi,Nakajima, Makoto,Hashimoto, Shunichi
, p. 1259 - 1260 (2007/10/03)
A highly stereocontrolled 1,2-cis-α-glycosidation reaction under conditions mild enough for acid-labile alcohols has been developed using benzyl-protected glycopyranosyl diethyl phosphites as glycosyl donors in the presence of 2,6-di-tert-butylpyridinium
