72366-52-0Relevant academic research and scientific papers
Stereoselective O-Glycosylations by Pyrylium Salt Organocatalysis**
Nielsen, Michael Martin,Holmstr?m, Thomas,Pedersen, Christian Marcus
, (2021/12/30)
Despite many years of invention, the field of carbohydrate chemistry remains rather inaccessible to non-specialists, which limits the scientific impact and reach of the discoveries made in the field. Aiming to increase the availability of stereoselective
Metal-free glycosylation with glycosyl fluorides in liquid SO2
Gulbe, Krista,Lugi?ina, Jevge?ija,Jansons, Edijs,Kinens, Artis,Turks, Māris
supporting information, p. 964 - 976 (2021/05/05)
Liquid SO2 is a polar solvent that dissolves both covalent and ionic compounds. Sulfur dioxide possesses also Lewis acid properties, including the ability to covalently bind Lewis basic fluoride ions in a relatively stable fluorosulfite anion (FSO2?). Herein we report the application of liquid SO2 as a promoting solvent for glycosylation with glycosyl fluorides without any external additive. By using various temperature regimes, the method is applied for both armed and disarmed glucose and mannose-derived glycosyl fluorides in moderate to excellent yields. A series of pivaloyl-protected O- and S-mannosides, as well as one example of a C-mannoside, are synthesized to demonstrate the scope of the glycosyl acceptors. The formation of the fluorosulfite species during the glycosylation with glycosyl fluorides in liquid SO2 is proved by 19F NMR spectroscopy. A sulfur dioxide-assisted glycosylation mechanism that proceeds via solvent separated ion pairs is proposed, whereas the observed α,β-selectivity is substrate-controlled and depends on the thermodynamic equilibrium.
Visible-light-promoted 3,5-dimethoxyphenyl glycoside activation and glycosylation
Cao, Yafei,Li, Qin,Liu, Da-Ke,Liu, Jianhui,Mao, Run-Ze,Xia, Feng,Xiong, De-Cai,Ye, Xin-Shan,Zhou, Minmin,Zou, You
supporting information, p. 10899 - 10902 (2021/10/25)
A new glycosylation method promoted by visible light with 3,5-dimethoxyphenyl glycoside as the donor was developed. This protocol delivers bothO-glycosides andN-glycosides in moderate to excellent yields using a wide range ofO-nucleophiles and nucleobases as the glycosyl acceptors.
Stereoselective β-mannosylations and β-rhamnosylations from glycosyl hemiacetals mediated by lithium iodide
McGarrigle, Eoghan M.,Pepe, Dionissia A.,Pongener, Imlirenla,Ruddy, Joseph J.
, p. 10070 - 10075 (2021/08/04)
Stereoselective β-mannosylation is one of the most challenging problems in the synthesis of oligosaccharides. Herein, a highly selective synthesis of β-mannosides and β-rhamnosides from glycosyl hemi-acetals is reported, following a one-pot chlorination,
An Unexpected FeCl 3/C-Catalyzed β-Stereoselective Glycosylation in the Presence of the C(2)-Benzyl Group
Guo, Hong,Li, Juan,Si, Wenshuai,Tang, Jie,Tang, Tianjun,Wang, Zhongfu,Yang, Guofang,Zhang, Jianbo
, p. 2984 - 3000 (2019/07/22)
An efficient and completely β-stereoselective glycosylation that did not rely on neighboring group participation is described using 2-20 molpercent FeCl 3 /C as the catalyst and benzylated propargyl glycosides as the donors to reach yields up to 96percent under mild condition. With an octatomic-ring intermediate at the α-face of FeCl 3 /C with alkyne of propargyl glycosides, a panel of aglycones comprising aliphatic, alicyclic, unsaturated alcohols, halogenated alcohols, and phenols with different substitution were examined successfully for the exclusive β-stereoselective glycosylation reaction.
Copper-Catalyzed Anomeric O-Arylation of Carbohydrate Derivatives at Room Temperature
Verdelet, Tristan,Benmahdjoub, Sara,Benmerad, Belkacem,Alami, Mouad,Messaoudi, Samir
, p. 9226 - 9238 (2019/08/12)
Direct and practical anomeric O-arylation of sugar lactols with substituted arylboronic acids has been established. Using copper catalysis at room temperature under an air atmosphere, the protocol proved to be general, and a variety of aryl O-glycosides have been prepared in good to excellent yields. Furthermore, this approach was extended successfully to unprotected carbohydrates, including α-mannose, and it was demonstrated here how the interaction between carbohydrates and boronic acids can be combined with copper catalysis to achieve selective anomeric O-arylation.
Copper-mediated anomeric: O -arylation with organoboron reagents
Dimakos, Victoria,Liu, Jacklyn J. W.,Ge, Zhenlu,Taylor, Mark S.
supporting information, p. 5671 - 5674 (2019/06/18)
Copper-mediated couplings of arylboroxines with glycosyl hemiacetals furnish O-aryl glycosides via Csp2-O bond formation. The method enables the anomeric O-arylation of protected pyranose and furanose derivatives, and is tolerant of functionalized arylboroxine partners. Whereas mixtures of anomers are formed from glucopyranose, galactopyranose and arabinofuranose hemiacetals, the α-anomer is generated selectively from mannopyranose and mannofuranose-derived substrates.
Reengineering Chemical Glycosylation: Direct, Metal-Free Anomeric O-Arylation of Unactivated Carbohydrates
Lucchetti, Nicola,Gilmour, Ryan
, p. 16266 - 16270 (2018/10/24)
To sustain innovation in glycobiology, effective routes to well-defined carbohydrate probes must be developed. For over a century, glycosylation has been dominated by the formation of the anomeric Csp3?O acetal junction in glycostructures. A dissociative mechanistic spectrum spanning SN1 and SN2 is frequently operational thereby reducing the efficiency. By reengineering this fundamental process, an orthogonal disconnection allows the acetal to be formed directly from the reducing sugar without the need for substrate pre-functionalisation. The use of stable aryliodonium salts facilitates a formal O?H functionalisation reaction. This allows lactols to undergo mild, metal-free O-arylation at ambient temperature. The efficiency of the transformation has been validated using a variety of pyranoside and furanoside monosaccharides in addition to biologically relevant di- and trisaccharides (up to 85 %). Fluorinated mechanistic probes that augment the anomeric effect were employed. It is envisaged that this strategy will prove expansive for the construction of complex acetals under substrate-based stereocontrol.
Synthesis of Phenolic Glycosides: Glycosylation of Sugar Lactols with Aryl Bromides via Dual Photoredox/Ni Catalysis
Ye, Hui,Xiao, Cong,Zhou, Quan-Quan,Wang, Peng George,Xiao, Wen-Jing
, p. 13325 - 13334 (2018/11/02)
Multifarious sugar lactols were efficiently transformed into the corresponding phenolic glycosides by treating with aryl bromides in acetonitrile with Ir[dF(CF3)ppy]2(dtbbpy)(PF6) as a photocatalyst under visible light irr
Dehydrative glycosylation with cyclic phosphonium anhydrides
Dyapa, Rajendar,Dockery, Lance T.,Walczak, Maciej A.
supporting information, p. 51 - 55 (2016/12/27)
Cyclic phosphonium anhydrides generated from bis-phosphine oxides and trifluoromethanesulfonic anhydride are shown as general coupling reagents in a dehydrative glycosylation reaction of C1-hemiacetals. This reaction protocol is characterized by a broad substrate scope and high yields, including reactions of O-, C-, N-, and S-based nucleophiles with furanose, pyranose, and deoxysugar donors.
