7177-79-9Relevant articles and documents
Substrate Substitution in Kanosamine Biosynthesis Using Phosphonates and Phosphite Rescue
Palmer, David R. J.,Vetter, Natasha D.
, p. 1926 - 1932 (2021/06/28)
Kanosamine is an antibiotic and antifungal compound synthesized from glucose 6-phosphate (G6P) inBacillus subtilisby the action of three enzymes: NtdC, which catalyzes NAD-dependent oxidation of the C3-hydroxyl; NtdA, a PLP-dependent aminotransferase; and
Synthesis of methyl 4,6-di-o-ethyl-α-d-glucopyranoside-based azacrown ethers and their effects in asymmetric reactions
Bagi, Péter,Bakó, Péter,Heged?s, László,Orbán, István,Rapi, Zsolt,Varga, Bertalan
, (2021/08/12)
Carbohydrate-based crown ethers have been reported to be able to generate asymmetric induction in certain reactions. Previously, it was proved that the monosaccharide unit, the anomeric substituent, and the sidearm could influence the catalytic activity of the monoaza-15-crown-5 macrocycles derived from sugars. In order to gain information about the effect of the flexibility, 4,6-di-O-ethyl-glucoside-based crown compounds were synthesized, and their efficiency was compared to the 4,6-O-benzylidene analogues. It was found that the absence of the two-ring annulation has a negative effect on the enantioselectivity in liquid-liquid two-phase reactions: in the Darzens condensation of 2-chloroacetophenone and in the epoxidation of chalcone. The same trend was observed in the solid-liquid phase Michael addition of diethyl acetamidomalonate. Surprisingly, in the solid-liquid phase cyclopropanation of benzylidenemalononitrile, one of the new catalysts was highly enantioselective (99% ee).
Triethylamine-methanol mediated selective removal of oxophenylacetyl ester in saccharides
Rasool, Javeed Ur,Kumar, Atul,Ali, Asif,Ahmed, Qazi Naveed
supporting information, p. 338 - 347 (2021/01/29)
A highly selective, mild, and efficient method for the cleavage of oxophenylacetyl ester protected saccharides was developed using triethylamine in methanol at room temperature. The reagent proved successful against different labile groups like acetal, ketal, and PMB and also generated good yields of the desired saccharides bearing lipid esters. Further, we also observed DBU in methanol as an alternative reagent for the deprotection of acetyl, benzoyl, and oxophenylacetyl ester groups. This journal is
Automated Quantification of Hydroxyl Reactivities: Prediction of Glycosylation Reactions
Chang, Chun-Wei,Lin, Mei-Huei,Chan, Chieh-Kai,Su, Kuan-Yu,Wu, Chia-Hui,Lo, Wei-Chih,Lam, Sarah,Cheng, Yu-Ting,Liao, Pin-Hsuan,Wong, Chi-Huey,Wang, Cheng-Chung
, p. 12413 - 12423 (2021/05/03)
The stereoselectivity and yield in glycosylation reactions are paramount but unpredictable. We have developed a database of acceptor nucleophilic constants (Aka) to quantify the nucleophilicity of hydroxyl groups in glycosylation influenced by the steric, electronic and structural effects, providing a connection between experiments and computer algorithms. The subtle reactivity differences among the hydroxyl groups on various carbohydrate molecules can be defined by Aka, which is easily accessible by a simple and convenient automation system to assure high reproducibility and accuracy. A diverse range of glycosylation donors and acceptors with well-defined reactivity and promoters were organized and processed by the designed software program “GlycoComputer” for prediction of glycosylation reactions without involving sophisticated computational processing. The importance of Aka was further verified by random forest algorithm, and the applicability was tested by the synthesis of a Lewis A skeleton to show that the stereoselectivity and yield can be accurately estimated.
How do Various Reaction Parameters Influence Anomeric Selectivity in Chemical Glycosylation with Thioglycosides and NIS/TfOH Activation?
Andersen, Sofie M.,Heuckendorff, Mads,Jensen, Henrik H.,Trinderup, Helle H.
, p. 3251 - 3259 (2021/06/25)
The reaction of glycosyl donor phenyl 2,3,4,6-tetra-O-benzyl-1-thio-β-D-glucopyranoside with NIS/TfOH(cat.) was systematically studied under various reaction conditions. Neither the molecular sieve pore size nor amount of NIS activator was found to have a
Carbocyclic Substrate Analogues Reveal Kanosamine Biosynthesis Begins with the α-Anomer of Glucose 6-Phosphate
Vetter, Natasha D.,Jagdhane, Rajendra C.,Richter, Brett J.,Palmer, David R. J.
, p. 2205 - 2211 (2020/09/01)
NtdC is an NAD-dependent dehydrogenase that catalyzes the conversion of glucose 6-phosphate (G6P) to 3-oxo-glucose 6-phosphate (3oG6P), the first step in kanosamine biosynthesis in Bacillus subtilis and other closely-related bacteria. The NtdC-catalyzed r
Stereoselective Phenylselenoglycosylation of Glycals Bearing a Fused Carbonate Moiety toward the Synthesis of 2-Deoxy-β-galactosides and β-Mannosides
Li, Zhongjun,Meng, Shuai,Yao, Wang,Zhong, Wenhe
supporting information, (2020/04/09)
A phenylselenoglycosylation reaction of glycal derivatives mediated by diphenyl diselenide and phenyliodine(III) bis(trifluoroacetate) under mild conditions is described. Stereoselective glycosylation has been achieved by installing fused carbonate on those glycals. 3,4-O-Carbonate galactals and 2,3-O-carbonate 2-hydroxyglucals are converted into corresponding glycosides in good yields with excellent β-selectivity, resulting in 2-phenylseleno-2-deoxy-β-galactosides and 2-phenylseleno-β-mannosides which are good precursors of 2-deoxy-β-galactosides and β-mannosides, respectively.
Mapping mechanisms in glycosylation reactions with donor reactivity: Avoiding generation of side products
Wang, Cheng-Chung,Chang, Chun-Wei,Lin, Mei-Huei,Wu, Chia-Hui,Chiang, Tsun-Yi
, p. 15945 - 15963 (2021/01/18)
The glycosylation reaction, which is key for the studies on glycoscience, is challenging due to its complexity and intrinsic side reactions. Thioglycoside is one of the most widely used glycosyl donors in the synthesis of complex oligosaccharides. However, one of the challenges is its side reactions, which lower its yield and limits its efficiency, thereby requiring considerable effort in the optimization process. Herein, we reported a multifaceted experimental approach that reveals the behaviors of side reactions, such as the intermolecular thioaglycon transformation and N-glycosyl succinimides, via the glycosyl intermediate. Our mechanistic proposal was supported by low temperature NMR studies that can further be mapped by utilizing relative reactivity values. Accordingly, we also presented our findings to suppress the generation of side products in solving this particular problem for achieving high-yield glycosylation reactions.
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
, 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.
Assessing the Optimal Deoxygenation Pattern of Dodecyl Glycosides for Antimicrobial Activity Against Bacillus anthracis
Dias, Catarina,Martins, Alice,Pelerito, Ana,Oliveira, Maria C.,Contino, Marialessandra,Colabufo, Nicola A.,Rauter, Amélia P.
, p. 2224 - 2233 (2019/02/19)
The discovery of the bactericide dodecyl 2,6-dideoxypyranoside reorganizing membrane phospholipid matrix of Bacillus species into a hexagonal phase, encouraged further research on glycone deoxygenation/bioactivity relationship. We now describe expedient syntheses of new 2-, 3-, 4-deoxy, 2,3- and 3,4-dideoxy glycosides in moderate to good yields. Interestingly, Amberlyst 15 is a key protagonist, efficiently applied for the transacetalation of alkyl deoxy glycosides and for ring contraction to access regioselectively hexofuranosides. The 2-deoxy-d-arabino pyranoside affords the higher MIC values against two Bacillus spp. and Enterococcus faecalis, while a 4-fold decrease or higher was found by inversion of configuration or by deoxygenation at C-3. While 2,3- and 3,4-dideoxygenation do not improve bioactivity, the 4,6-dideoxy-α-d-xylo-hexopyranoside remains a promising glycoside, presenting low MIC values for all species tested, and low cytotoxicity in intestinal and liver cell models.