Article
Biochemistry & Molecular Biology
Nicolas Jouandon, Jana Hammoud, Alexandre Touron, Laetitia Bailly, Alexandra Le Foll, Antoine Y. P. Joosten, Thomas Lecourt
Summary: In this study, supercritical fluid chromatography coupled to high-resolution mass spectrometry (SFC-HRMS) was used to identify a chloro glycoside generated during the preparation of propargyl 1,2-orthoesters in dichloromethane. Further investigation revealed that the yield of this byproduct ranged from 20 to 40% depending on the source of anhydrous solvent, and tetrabutylammonium iodide enhanced this side reaction. Finally, a reliable procedure was developed in acetonitrile to synthesize these glycosyl donors from perbenzoylated bromo glycosides in the manno, gluco, and galacto series with yields of 63-74%.
CARBOHYDRATE RESEARCH
(2022)
Article
Chemistry, Organic
Daiki Takeda, Makoto Yoritate, Hiroki Yasutomi, Suzuka Chiba, Takahiro Moriyama, Atsushi Yokoo, Kazuteru Usui, Go Hirai
Summary: C-Glycosides are metabolically stable mimics of natural O-glycosides, synthesized through stereoinvertive sp(3)-sp(2) cross-coupling reactions using a photoredox/nickel dual catalytic system. The hydrogenation of vinyl C-glycosides leads to C-linked 2'-deoxydisaccharide analogues.
Article
Chemistry, Multidisciplinary
Xiaoqian Li, Zhi Ma, Rongkun Liu, Mattan Hurevich, You Yang
Summary: A green and efficient photolabile protecting group (PPG)-mediated glycosidation approach for the synthesis of 2-deoxy-glycosides is reported. Multiple oNBC groups in the 2-deoxy-glycosides can be completely cleaved by irradiation at 365 nm, resulting in the desired 2-deoxy-glycosides in an efficient manner. Oligosaccharides with three to six oNBC groups are effectively achieved based on this PPG-mediated glycosidation approach.
CHINESE JOURNAL OF CHEMISTRY
(2021)
Article
Chemistry, Organic
Liming Shao, Zhenni Huo, Na Lei, Min Yang, Zehuan He, Yongliang Zhang, Qinlong Wei, Changsheng Chen, Mei Xiao, Fei Wang, Guofeng Gu, Feng Cai
Summary: N,N-Diacetylimido protection of 2-aminoglycosides is an elegant strategy with limited applications due to unexpected side reactions in glycosylation. High acid concentrations can diminish the side reactions. Inter-molecular hydrogen bonding among alcohols and acids may cause disruption in this process. By disrupting the inter-molecular hydrogen bonds, the desired glycosylation can be achieved.
JOURNAL OF ORGANIC CHEMISTRY
(2021)
Article
Chemistry, Physical
Paul M. DeMent, Chenlu Liu, Joseph Wakpal, Richard N. Schaugaard, H. Bernhard Schlegel, Hien M. Nguyen
Summary: Phenanthroline is a commonly used bidentate ligand in coordination chemistry, which can be tuned to develop efficient and stereoselective catalysts. By activating 2-deoxy-2-fluoro glycosyl halides with phenanthroline-based catalysts, glycosylations with high levels of alpha-selectivities and moderate to high yields can be achieved. The proposed mechanism for this catalytic glycosylation system involves double S(N)2 displacement pathways with phenanthroline catalysts, ensuring stereoselective formation of alpha-1,2-cis-2-fluoro glycosides.
Article
Chemistry, Organic
Yuling Mei, Nan Jiang, Yu Yang, Wan Zhang, Saifeng Qiu, Hong Guo, Jianbo Zhang
Summary: A convenient protocol for the beta-stereoselective synthesis of 2-deoxy- C -arylglycosides has been developed, involving one-step reaction using I (2) /Et (3) SiH. The approach is applicable to a wide range of naphthol moieties and was demonstrated to be effective in the synthesis of 5-aza analogues of aquayamycin.
Article
Biochemistry & Molecular Biology
Serena Traboni, Emiliano Bedini, Domenica Capasso, Fabiana Esposito, Alfonso Iadonisi
Summary: Researchers have found that 1,2-trans methyl glycosides can be easily obtained by converting peracetylated sugars into glycosyl iodide donors and treating them with sodium methoxide in methanol. This method also allows for the synthesis of 1,2-trans glycosides with concomitant de-O-acetylation in satisfying yields using GlcNAc glycosyl chloride as the donor.
CARBOHYDRATE RESEARCH
(2023)
Article
Chemistry, Organic
Jordi Mestre, Isabel Bascuas, Miguel Bernus, Sergio Castillon, Omar Boutureira
Summary: Fluorinated carbohydrate mimetics are important in Glycoscience, but the synthesis of complex C(sp(3))-CF3 congeners is underdeveloped. A new protocol for preparing 2-deoxy-2-trifluoromethyl-d-hexopyranosides from d-glycals is presented. The stereoselectivity of glycosylation is mainly controlled by electronic and steric factors, resulting in the formation of 1,2-trans glycosides due to the configuration of the CF3 moiety at C-2. This approach was successfully applied in the synthesis of 2-CF3-glycoconjugates of natural origin.
ORGANIC CHEMISTRY FRONTIERS
(2023)
Article
Chemistry, Organic
Wen-Ze Shi, Hai Li, Gui-Cai Mu, Ji-Liang Lu, Yuan-Hong Tu, Xiang-Guo Hu
Summary: The study reports for the first time that imidate radicals can efficiently add to glycals to produce glycosyl radicals, leading to a general, toxic-reagent-free synthesis of C-glycosides of 2-deoxy-2-amino sugars. The reaction is 1,2-trans-stereoselective and can utilize aryl alkenes as substrates. Late-stage functionalization and density functional theory calculations have been reported.
Article
Chemistry, Inorganic & Nuclear
Younian Tang, Fan Wu, Huiying Chen, Jia-Lu Chai, Xu-Dong Chen, Bin Xi
Summary: Atomic layer deposition (ALD) relies on precursor design and synthesis for fabricating thin film materials. A synthetic route has been developed to introduce (trimethylsilyl)methyl ligand into the coordination sphere of mo-lybdenum, leading to the synthesis of an unprecedented compound. The synthesis method provides an easier way to synthesize a recently patented analogous compound and offers a useful method for the introduction of the ligand toward potential ALD precursors. The thermal stability and volatility of the two potential ALD precursors were also evaluated.
INORGANIC CHEMISTRY COMMUNICATIONS
(2023)
Article
Chemistry, Inorganic & Nuclear
Eva M. Zolnhofer, Adedamola A. Opalade, Timothy A. Jackson, Frank W. Heinemann, Karsten Meyer, J. Krzystek, Andrew Ozarowski, Joshua Telser
Summary: The study characterized the ground-state electronic structure of the octahedral coordination complex trans-[CrCl2(dmpe)(2)] using high-frequency and high-field electron paramagnetic resonance (HFEPR) spectroscopy. The complex was found to have a complex electronic structure, which was well reproduced by computational methods.
INORGANIC CHEMISTRY
(2021)
Article
Chemistry, Multidisciplinary
Xin Qiu, Anna L. Garden, Antony J. Fairbanks
Summary: In this study, a new method for synthesizing glycosides was discovered. Unprotected 2-acetamido sugars were directly converted into their oxazolines in aqueous solution using 2-chloro-1,3-dimethylimidazolinium chloride (DMC) and a suitable base. Freeze drying and acid-catalyzed reaction with an alcohol as solvent yielded 1,2-trans-glycosides in good yield. Alternatively, using an aprotic solvent system and acidic activation with an excess of unprotected glycoside as a glycosyl acceptor led to the stereoselective formation of 1,2-trans-linked disaccharides without any protecting group manipulations. Reactions using aryl glycosides as acceptors were completely regioselective, producing only (1->6)-linked disaccharides.
Review
Chemistry, Organic
Nayyef Aljaar, Mohammad M. Ibrahim, Eyad A. Younes, Mousa Al-Noaimi, Kayed A. Abu-Safieh, Basem F. Ali, Kamal Kant, Nabil Al-Zaqri, Ragini Sengupta, Chandi C. Malakar
Summary: This review summarizes the important breakthrough achieved in the last decade in the synthesis of compounds attached to 2-keto aryl azole moieties, which play a crucial role in medicinal chemistry and drug discovery.
ASIAN JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Chemistry, Organic
Mosidur Rahaman Molla, Rima Thakur
Summary: The use of (1 N/2 N)-methylated tetrazole methyl ethers as a C2-directing group for the formation of 1,2-trans-beta-O-glycosides, in combination with the activation of tethered thioglycoside donors by PIFA-TfOH reagent system, allows for efficient glycosylation reactions with high selectivity.
EUROPEAN JOURNAL OF ORGANIC CHEMISTRY
(2021)
Article
Chemistry, Organic
Madhu Babu Tatina, Mohammad Saif Ali, P. Ramesh, Subhash Ghosh
Summary: We present a strategy for the stereoselective synthesis of 1,2-trans-glycosides in the absence of neighboring group participation. The protocol relies on catalyst control instead of protecting group selection, and has been successfully applied for the preparation of various glycosides.
