Article
Chemistry, Organic
Wang Jingrui, Feng Yongkui, Wang Nengzhong, Huang Nianyu, Yao Hui
Summary: C-Glycosides have attracted attention in the fields of medicine and biology due to their physiological activities and stability. This paper reports a method for preparing high stereoselectivity beta-C-glycosides through a specific reaction at room temperature, providing a reliable method for the rapid construction of C-glycoside libraries.
CHINESE JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Chemistry, Multidisciplinary
Wanjun Zhu, Qikai Sun, Hai Chang, Hui-Xing Zhang, Quanquan Wang, Gong Chen, Gang He
Summary: A new protocol for the synthesis of 2-deoxy-C-aryl-glycosides and 2-deoxy-C-alkyl-glycosides via iridium-catalyzed directed C-H glycosylation with glycals is reported. The benzoxazole directing group can be cleanly removed by the treatment of KOH or LiAlH4, offering a versatile method for the synthesis of these glycosides.
CHINESE JOURNAL OF CHEMISTRY
(2022)
Article
Chemistry, Multidisciplinary
Aleksandra Blocka, Jakub Ostapko, Wojciech Chaladaj
Summary: For the first time, a cascade reaction involving a 5-exo-dig intramolecular nucleophilic addition of an enamine to a terminal alkyne followed by cross coupling has been demonstrated. This reaction allows for the stereoselective formation of two new C-C bonds using a single Pd-complex capable of catalyzing two mechanistically diverse transformations. Mechanistic investigations revealed that cyclization, relying on the facile displacement of OTf weakly bound to the Pd-center by the alkyne, is the rate limiting step.
CHEMICAL COMMUNICATIONS
(2023)
Article
Chemistry, Multidisciplinary
Daigo Hayashi, Tomohiro Tsuda, Ryo Shintani
Summary: A palladium-catalyzed skeletal rearrangement has been developed to synthesize highly fused tetrahydrophenanthrosilole derivatives via bond exchange. The reaction conditions can be tuned to produce different products, fused dihydrodibenzosilepin derivatives.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Multidisciplinary
Qikai Sun, Huixing Zhang, Quanquan Wang, Tianjiao Qiao, Gang He, Gong Chen
Summary: A new strategy has been developed for the stereoselective synthesis of C-vinyl glycosides, using Pd-catalyzed directed C-H glycosylation. This method offers a broadly applicable approach to streamline the synthesis of complex C-vinyl glycosides with high efficiency and excellent regio- and stereoselectivity.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Organic
Wei-Yi Ding, Hao-Wen Zhao, Jun Kee Cheng, Zhiqiang Lu, Shao-Hua Xiang, Bin Tan
Summary: This report describes a highly efficient beta-selective C-glycosylation reaction using bicyclic galactals and 2-oxindoles as substrates. The reaction proceeds through a palladium-catalyzed decarboxylative pathway under mild reaction conditions, resulting in high yields. The decarboxylation intermediate of galactal acts as an efficient base to deprotonate the enol tautomer of 2-oxindole, enhancing its nucleophilicity. The beta-selective nucleophilic addition at the anomeric center is due to steric hindrance imposed by the palladium and bulky ligand.
Article
Chemistry, Multidisciplinary
Anselme Geulin, Yann Bourne-Branchu, Kawther Ben Ayed, Thomas Lecourt, Antoine Joosten
Summary: 3-Amino-3-deoxyglycosides are important nitrogen-containing sugars, with many important ones having a 1,2-trans configuration. The synthesis of 3-amino-3-deoxyglycosyl donors that can form a 1,2-trans glycosidic linkage is a significant challenge due to their biological applications. This work presents a new sequence involving Ferrier rearrangement and subsequent aza-Wacker cyclization for the rapid synthesis of orthogonally protected 3-amino-3-deoxyglycals. Additionally, the epoxidation/glycosylation of a 3-amino-3-deoxygalactal derivative was successfully achieved with high yield and diastereoselectivity, demonstrating FAWEG as a new approach for accessing 1,2-trans 3-amino-3-deoxyglycosides.
CHEMISTRY-A EUROPEAN JOURNAL
(2023)
Article
Biochemistry & Molecular Biology
Xueying You, Yifei Cai, Chenyu Xiao, Lijuan Ma, Yong Wei, Tianpeng Xie, Lei Chen, Hui Yao
Summary: An effective and direct methodology using AgOTf as a catalyst has been developed for the stereoselective synthesis of alpha-2-deoxythioglycosides. This method not only allows the synthesis of disaccharides, but also enables successful late-stage glycosylation of estrogen, L-menthol, and zingerone with thiol compounds.
Review
Chemistry, Physical
Anrong Chen, Bo Yang, Zhenghong Zhou, Feng Zhu
Summary: Chemical synthesis is an effective strategy for carbohydrate synthesis, allowing precise control of sugar chain structure. Researchers have focused on developing stereoselective glycosylation to access carbohydrate mimics, resulting in remarkable progress. Transition-metal-catalyzed glycosylation reactions have emerged as a powerful tool for the synthesis of various glycosides and glycoconjugates due to their versatility, efficiency, and stereoselectivity.
Article
Chemistry, Organic
Juyeol Lee, Young Ho Rhee
Summary: This study presents a palladium-catalyzed polar inversion reaction where glycals and their isomers can act as nucleophiles. The reaction exhibits high regio- and stereoselectivity in the presence of various aromatic and aliphatic aldehydes, demonstrating its synthetic utility in the concise synthesis of the tetrahydropyran fragment of the anticancer natural product mucocin.
Article
Chemistry, Applied
Atul Dubey, Neha Singh Chauhan, Zanjila Azeem, Pintu Kumar Mandal
Summary: A Pd(II)-catalyzed, bidentate directing group (BDG)-assisted C(sp(2))-H functionalization of C2-amido glycals onto the anomeric position is reported as a contemporary approach for the synthesis of various unsymmetrical gem-diarylmethyl C-glycosides. The use of a bidentate amidoquinoline-type directing group enables the insertion of different para-quinone methides (p-QMs) onto the pseudo-anomeric position of glycal substrates, yielding moderate to good yields. The final product can be further functionalized through known palladium-catalyzed cross-coupling reactions.
ADVANCED SYNTHESIS & CATALYSIS
(2023)
Article
Chemistry, Organic
Kim Greis, Caleb E. Griesbach, Carla Kirschbaum, Gerard Meijer, Gert von Helden, Kevin Pagel, Mark W. Peczuh
Summary: Ferrier reactions involve Lewis acid activation of a cyclic enol ether to generate a glycosyl Ferrier cation through the departure of an allylic leaving group. The resulting cation undergoes attack and transposition, forming a new acetal linkage. This study focuses on the septanosyl Ferrier cation derived from a seven-membered ring carbohydrate-based oxepine. Experimental characterization of the ion, including gas-phase cryogenic IR spectroscopy and solution-phase Ferrier reactions, reveals a preference for contraction to five-membered ring structures in the cation.
JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Chemistry, Multidisciplinary
Xiang Li, Gao-Wei Wang, Li-Xia Liu, Chang-Bin Yu, Yong-Gui Zhou
Summary: Here, the authors describe the first example of palladium-catalyzed asymmetric hydrogenolysis of easily accessible aryl triflates for the construction of axially chiral biaryl scaffolds. The resulting chiral biaryl compounds were used to prepare axially chiral monophosphine ligands, which were further employed in palladium-catalyzed asymmetric allylic alkylation with excellent enantioselectivities and high branched and linear ratios, highlighting the potential utility of this methodology.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Organic
Pan Gao, Qingzheng Zhang, Feng Chen
Summary: A new protocol for vinyl sulfide synthesis has been developed using an alkoxy base without the need for metal catalysts. This method allows for the conversion of aryl and alkenyl sulfonium triflates with various functionalities into vinyl sulfides with excellent reactivity. The reaction conditions are mild and safe, without the use of catalysts, transition metals, high-pressure gases, or high temperatures, while still maintaining efficiency.
Article
Chemistry, Organic
Bryant Pero, Mark W. Peczuh
Summary: A new synthesis of carbohydrate-based oxepines using 2,3;4,6-di-O-acetonide mannose as a key starting material is reported. The oxepine is an important precursor used in the synthesis of septanose glycomimetics of mannopyranosides.
JOURNAL OF ORGANIC CHEMISTRY
(2022)
