Organic Letters, Год журнала: 2022, Номер 24(19), С. 3461 - 3465
Опубликована: Май 6, 2022
Chemical synthetic efforts have resulted in the preparation of assigned tetrasaccharide repeating subunit from Acinetobacter baumannii KL4-associated capsular polysaccharide. A convergent strategy hinging on a 1,2-cis-selective [2+2] glycosylation to generate fully protected was key success this synthesis.
Язык: Английский
Chemical Society Reviews, Год журнала: 2023, Номер 52(22), С. 7773 - 7801
Опубликована: Янв. 1, 2023
The structural complexity of glycans poses a serious challenge in the chemical synthesis glycosides, oligosaccharides and glycoconjugates. Glycan complexity, determined by composition, connectivity, configuration far exceeds what nature achieves with nucleic acids proteins. Consequently, glycoside ranks among most complex tasks organic synthesis, despite involving only simple type bond-forming reaction. Here, we introduce fundamental principles bond formation summarize recent advances oligosaccharide synthesis.
Язык: Английский
Процитировано
46
ACS Central Science, Год журнала: 2021, Номер 7(9), С. 1454 - 1462
Опубликована: Авг. 13, 2021
With a view to reducing the notorious complexity and irreproducibility of glycosylation reactions, 12 guidelines for choice concentration, temperature, counterions are adumbrated.
Язык: Английский
Процитировано
66
Science, Год журнала: 2023, Номер 382(6673), С. 928 - 935
Опубликована: Ноя. 23, 2023
Despite their importance in life and material sciences, the efficient construction of stereo-defined glycosides remains a challenge. Studies carbohydrate functions would be advanced if glycosylation methods were as reliable modular palladium (Pd)-catalyzed cross-coupling. However, Pd-catalysis excels forming sp 2 -hybridized carbon centers whereas mostly builds 3 C–O linkages. We report platform through Pd-catalyzed S N displacement from phenols toward bench-stable, aryl-iodide–containing glycosyl sulfides. The key Pd(II) oxidative addition intermediate diverges an arylating agent (Csp electrophile) to glycosylating electrophile). This method inherits many merits cross-coupling reactions, including operational simplicity functional group tolerance. It preserves mechanism for various substrates is amenable late-stage commercial drugs natural products.
Язык: Английский
Процитировано
31
Nature, Год журнала: 2024, Номер 632(8024), С. 313 - 319
Опубликована: Июнь 17, 2024
Язык: Английский
Процитировано
17
Accounts of Chemical Research, Год журнала: 2024, Номер 57(11), С. 1577 - 1594
Опубликована: Апрель 16, 2024
Carbohydrates are called the third chain of life. participate in many important biochemical functions living species, and biological information carried by them is several orders magnitude larger than that nucleic acids proteins. However, due to intrinsic complexity heterogeneity carbohydrate structures, furnishing pure structurally well-defined glycans for functional studies a formidable task, especially homogeneous large-size glycans. To address this issue, we have developed donor preactivation-based one-pot glycosylation strategy enabling multiple sequential glycosylations single reaction vessel.The refers which glycosyl activated absence acceptor generate reactive intermediate. Subsequently, with same anomeric leaving group added, leading coupling reaction, then iterated rapidly achieve desired glycan reactor. The advantages include following: (1) unique chemoselectivity obtained after preactivation; (2) it independent reactivity donors; (3) multiple-step enabled without need intermediate purification; (4) only stoichiometric building blocks required complex protecting manipulations. Using protocol, range including tumor-associated antigens, various glycosaminoglycans,
Язык: Английский
Процитировано
10
Journal of the American Chemical Society, Год журнала: 2025, Номер unknown
Опубликована: Фев. 5, 2025
The formation of 1,2-trans-glycosides taking advantage neighboring group participation by stereodirecting esters at the 2-position glycosyl donors is widely held to be a robust and reliable protocol. Examples abound, however, cases in which less-than-perfect selectivity obtained, causing practitioners survey different or resort alternative strategies quest for optimal selectivities yields. Consideration mechanism particular competing process SN2-like glycosylation with activated covalent leads hypothesis that imperfect selectivity, more careful attention reaction concentration stoichiometry may beneficial. Three case studies are presented demonstrate dependence group-directed reactions targeting both 1,2-trans-equatorial 1,2-trans-axial glycosides. Higher concentrations, whether achieved through increased acceptor:donor fixed stoichiometry, mostly lead erosion 1,2-trans-selectivity as becomes increasingly important. These observations underline importance rational, mechanism-based approach general importantly suggest simple enhancing displaying 1,2-trans-selectivity, namely, moving regime.
Язык: Английский
Процитировано
1
Angewandte Chemie International Edition, Год журнала: 2022, Номер 61(15)
Опубликована: Янв. 15, 2022
Glycosidic bond formation is a continual challenge for practitioners. Aiming to enhance the reproducibility and efficiency of oligosaccharide synthesis, we studied relationship between glycosyl donor activation reaction temperature. A novel semi-automated assay revealed diverse responses members panel thioglycosides at various temperatures. The patterns protecting groups thiol aglycon combine cause remarkable differences in temperature sensitivity among building blocks. We introduce concept capture experimental insights, reasoning that glycosylations performed below this reference evade deleterious side reactions. Activation temperatures enable simplified treatment facilitate optimization usage. Isothermal glycosylation halved equivalents block required comparison standard "ramp" regime used solution- solid-phase synthesis to-date.
Язык: Английский
Процитировано
31
Frontiers in Chemistry, Год журнала: 2022, Номер 10
Опубликована: Авг. 19, 2022
For the stereoselective assembly of bioactive glycans with various functions, 1,2-
Язык: Английский
Процитировано
30
Chemical Science, Год журнала: 2023, Номер 14(6), С. 1532 - 1542
Опубликована: Янв. 1, 2023
The reactivity of the acceptor alcohol can have a tremendous influence on outcome glycosylation reaction, both in terms yield and stereoselectivity. Through systematic survey 67 alcohols reactions with two glucosyl donors we here reveal how carbohydrate depends its configuration substitution pattern. study shows functional groups flanking show that nature relative orientation play an essential role. empiric guidelines revealed will aid rational optimization be important tool assembly oligosaccharides.
Язык: Английский
Процитировано
18
Beilstein Journal of Organic Chemistry, Год журнала: 2021, Номер 17, С. 1981 - 2025
Опубликована: Авг. 5, 2021
The sequence, length and substitution of a polysaccharide influence its physical biological properties. Thus, sequence controlled polysaccharides are important targets to establish structure-properties correlations. Polymerization techniques enzymatic methods have been optimized obtain samples with well-defined patterns narrow molecular weight distribution. Chemical synthesis has granted access full control over the length. Here, we review progress towards polysaccharides. For each class polysaccharides, discuss available synthetic approaches their current limitations.
Язык: Английский
Процитировано
28