68601-73-0Relevant academic research and scientific papers
N-Heterocyclic silylene/germylene ligands in Au(i) catalysis
Parvin, Nasrina,Mishra, Bijoyananda,George, Anjana,Neralkar, Mahesh,Hossain, Jabed,Parameswaran, Pattiyil,Hotha, Srinivas,Khan, Shabana
supporting information, p. 7625 - 7628 (2020/08/25)
Cationic Au(i) complexes (2, 5 and 8) supported by N-heterocyclic carbene, silylene and germylene ligands were prepared and their potential as catalysts in glycosidation chemistry has been evaluated. Insights into the mechanism are provided using DFT studies. Practical application of them as catalysts was achieved by the synthesis of the branched pentamannan core of the HIV-gp120 envelope under mild conditions.
Dehydrative Glycosylation Enabled by a Comproportionation Reaction of 2-Aryl-1,3-dithiane 1-Oxide?
Cai, Lei,Zeng, Jing,Li, Ting,Xiao, Ying,Ma, Xiang,Xiao, Xiong,Zhang, Qin,Meng, Lingkui,Wan, Qian
supporting information, p. 43 - 49 (2019/11/28)
A new dehydrative glycosylation reaction has been established by capitalizing on the comproportionation reaction of 2-aryl-1,3-dithiane 1-oxides promoted by triflic anhydride (Tf2O). By wedding the high potency of thiophilic promoter system with the step efficiency of dehydrative glycosylation, this reagent underwent facile intermolecular oxothio acetalization with C1-hemiacetal donor to install a temporary leaving group, rendering a transient electrophilic center at the remote site to the anomeric position. The sulfenyl triflate tethered at the terminus concomitantly activated the sulfide intramolecularly to afford the oxocarbenium ion, thereby facilitating the title glycosylation. Aside from accommodating broad range functional groups and inactive hemiacetal substrates, the present activation protocol also proved expedient for 1,3-diol protection. Most importantly, this method further provided a fresh perspective for the application of sulfur chemistry to carbohydrate chemistry.
Nucleofuge Generating Glycosidations by the Remote Activation of Hydroxybenzotriazolyl Glycosides
Neralkar, Mahesh,Mishra, Bijoyananda,Hotha, Srinivas
, p. 11494 - 11504 (2017/11/10)
Hydroxybenzotriazole is routinely used in peptide chemistry for reducing racemization due to the increased reactivity. In this article, very stable hydroxybenzotriazolyl glucosides were identified to undergo glycosidation. The reaction was hypothesized to go through the remote activation by the Tf2O at the N3-site of HOBt followed by the extrusion of the oxocarbenium ion that was attacked by the glycosyl acceptor. Further, equilibration of the zwitterionic benzotriazolyl species makes the leaving group noncompetitive and generates the nucleofuge that has been reconverted to the glycosyl donor. The reaction is mild, high yielding, fast and suitable for donors containing both C2-ethers and C2-esters as well. The regenerative-donor glycosidation strategy is promising as it enables us to regenerate the glycosyl donor for further utilization. The utility of the methodology for the oligosaccharide synthesis was demonstrated by the successful synthesis of the branched pentamannan core of the HIV1-gp120 complex.
One-pot catalytic glycosidation/Fmoc removal - An iterable sequence for straightforward assembly of oligosaccharides related to HIV gp120
Pastore, Antonello,Adinolfi, Matteo,Iadonisi, Alfonso,Valerio, Silvia
experimental part, p. 711 - 718 (2010/03/24)
The removal of a transient Fmoc protecting group can be simply performed by the addition of excess Et3N just after the accomplishment of a Bi(OTf)3-promoted glycosidation reaction. The obtained oligosaccharide can be directly employed as a glycosyl acceptor for further elongation of the saccharide. The preparation of biologically important, linear and branched mannans incorporated into HIV gp 120 demonstrates that the iteration of this one-pot sequence leads to a very straightforward oligosaccharide assembly.
Rapid assembly of gp120 oligosaccharide moieties via one-pot glycosidation-deprotection sequences
Pastore, Antonello,Adinolfi, Matteo,Iadonisi, Alfonso,Valerio, Silvia
experimental part, p. 1316 - 1323 (2010/10/02)
Mannosyl trihaloacetimidate donors equipped with a 2-O-Fmoc group can be effectively activated by catalytic Bi(OTf)3 in glycosidations. Despite the expected participating effect of the Fmoc group, the reaction solvent was found to be decisive f
Synthesis of a nonasaccharide with two Lewis x trisaccharides anchored onto a branched trimannoside
Zhang,Brodzky,Sinay,Saint-Marcoux,Perly
, p. 1195 - 1216 (2007/10/02)
Double condensation of phenyl 3,4,6-tri-O-benzyl-2-O-[6-O-benzyl-2-deoxy-2-phthalimido-4-O-(2,3,4,6- tetra-O-benzoyl-β-D-galactopyranosyl)-3-O-(2,3,4-tri-O-benzyl-α-L-fu copyranosyl)-β-D-glucopyranosyl]-1-thio-α-D-mannopyranoside 31 with methyl 2,4-di-O-b
SYNTHETIC STUDIES ON CELL SURFACE GLYCANS 3 BRANCHING PENTASACCHARIDES OF GLYCOPROTEIN
Ogawa, Tomoya,Katano, Kiyoaki,Sasajima, Kikuo,Matsui, Masanao
, p. 2779 - 2786 (2007/10/02)
Synthetic routes for the branching pentasaccharides 4 and 5 of glycoproteins are described in a regio- and stereo-controlled way.
