210426-02-1Relevant articles and documents
Slow glycosylation: Activation of trichloroacetimidates under mild conditions using lithium salts and the role of counterions
Korber, Nora Katharina,Pedersen, Christian Marcus
supporting information, (2022/01/19)
Glycosylations were carried out with the two glycosyl donors 4-O-acetyl-2,3-O-isopropylidene-1-O-trichloroacetimidoyl-α-L-rhamnopyranose and 2,3,4-tri-O-benzyl-1-O-trichloro-acetimidoyl-α-L-rhamnopyranose in combination with the two alcohols 1-adamantanol and L-menthol as model glycosyl acceptors. As catalysts, the five lithium salts LiNTf2, LiI, LiClO4, LiPF6 and LiOTf were investigated. We demonstrated that both lithium and the respective counterions are playing a role in the activation of trichloroacetimidate glycosyl donors at rt. Under these very mild conditions, the glycosylations are slow and completed in two to eight days. Depending on the counterion, the rate and yield of the reaction differs; however, the selectivity of all investigated lithium salts is deficient.
Regioselective Anomeric O-Benzyl Deprotection in Carbohydrates
Anjaneyulu, Bandi,Rao, Boddu Umamaheswara,Sridhar, Perali Ramu
supporting information, p. 5665 - 5668 (2021/11/11)
A highly regioselective hydrogenolysis of the anomeric benzyl group is reported. The reaction involves selective acetolysis of benzyl acetals of various mono- and di-saccharides using 10 % Pd/C under hydrogen atmosphere in the presence of Na2CO
Synthesis of Rhamnolipid Derivatives Containing Ester Isosteres
Lowary, Todd L.,Wang, Lei
supporting information, p. 9633 - 9637 (2020/12/21)
Rhamnolipids are biosurfactants with many applications, arising from their inherent biological activity and their potential as bioremediation agents. Herein, we report the synthesis of four rhamnolipid derivatives in which the ester linkage connecting the
Palladium-Catalyzed ortho-C-H Glycosylation/ ipso-Alkenylation of Aryl Iodides
Ding, Ya-Nan,Shi, Wei-Yu,Liu, Ce,Zheng, Nian,Li, Ming,An, Yang,Zhang, Zhe,Wang, Cui-Tian,Zhang, Bo-Sheng,Liang, Yong-Min
, p. 11280 - 11296 (2020/10/12)
This report describes the first example of palladium-catalyzed ortho-C-H glycosylation/ipso-alkenylation of aryl iodides, and the easily accessible glycosyl chlorides are used as a glycosylation reagent. The reaction is compatible with the functional groups of the substrates, and a series of C-aryl glycosides have been synthesized in good to excellent yield and with excellent diastereoselectivity. It is found that a cheap 5-norbornene-2-carbonitrile as a transient mediator can effectively promote this reaction. In addition, ipso-arylation and cyanation were also realized by the strategy.
Glycosylation Enabled by Successive Rhodium(II) and Br?nsted Acid Catalysis
Meng, Lingkui,Wu, Peng,Fang, Jing,Xiao, Ying,Xiao, Xiong,Tu, Guangsheng,Ma, Xiang,Teng, Shuang,Zeng, Jing,Wan, Qian
, p. 11775 - 11780 (2019/08/20)
Herein, we reported on a highly efficient glycosylation reaction comprising two chronological meticulously designed catalytic cycles: (1) rhodium-catalyzed formation of sulfonium ylide and (2) Br?nsted acid-catalyzed formation of sulfonium ion. This protocol highlighted an effective and robust tactic to prepare a glycosyl sulfonium ion from a glycosyl sulfonium ylide precursor amenable for glycosylation.
BIARYL AMIDES WITH MODIFIED SUGAR GROUPS FOR TREATMENT OF DISEASES ASSOCIATED WITH HEAT SHOCK PROTEIN PATHWAY
-
, (2019/12/04)
Provided are biaryl amides and coumarin-based compounds with modified sugar groups for treatment of diseases associated with heat shock protein pathway. The compounds having the following formulas, wherein variables are as defined herein. Formulae (I), (II), (III), (IV), and (V), Pharmaceutical compositions of the compounds are also provided. These biaryl amides and coumarin-based derivatives with modified sugar groups are useful for treatment and prevention of diseases and disorders, including neurological disorders, such as neurodegenerative diseases and nerve damaging disorders, for example, diabetic peripheral neuropathy.
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
supporting information, 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
Synthesis of C-spiro-glycoconjugates from sugar lactones via zinc mediated Barbier reaction
Lambu, Mallikharjuna Rao,Hussain, Altaf,Sharma, Deepak K.,Yousuf, Syed Khalid,Singh, Baldev,Tripathi, Anil. K.,Mukherjee, Debaraj
, p. 11023 - 11028 (2014/03/21)
Anomeric gem-diallylation, mono-β-crotylation and mono-β- propargylation of sugar 1,5 and 1,4 lactones have been achieved under Barbier reaction conditions using Zn powder and a catalytic amount of TMSCl as an activator. Ring closing olefin metathesis of the synthesized gem-diallyl derivatives furnished C-spiro cyclopentene glycosides. Finally, the cyclopentene rings were converted into carbohydrate based tricyclic morpholine fused triazole glycoconjugates as potential SGLT2 inhibitors.
Synthesis of the rhamnosyl trisaccharide repeating unit to mimic the antigen determinant of Pseudomonas syringae lipopolysaccharide
Yu, Chung-Shan,Wang, Heng-Yen,Chiang, Li-Wu,Pei, Kai
, p. 1412 - 1420 (2008/02/13)
The trisaccharide 2,3,4-O-tribenzyl-α-L-rhamnosyl-(1→3)-4-O- acetyl-2-O-benzoyl-(1→2)-4-O-acetyl-3-O-benzoyl-α-L-rhamnosyl-1-(4- tolyl)thio-α-L-rhamnopyranoside was prepared from the thio-sugar 1-(4-tolyl)thio-α,β-L-rhamnopyranoside from the nonreducing e
NIS/H2SO4-Silica: a mild and efficient reagent system for the hydrolysis of thioglycosides
Dasgupta, Somnath,Roy, Bimalendu,Mukhopadhyay, Balaram
, p. 2708 - 2713 (2007/10/03)
Chemoselective hydrolysis of a variety of thioglycosides in the presence of a wide range of protecting groups has been achieved by using N-iodosuccinimide and H2SO4 immobilized on silica in good to excellent yields.