Regiodivergent Functionalization of Protected and Unprotected Carbohydrates using Photoactive 4‐Tetrafluoropyridinylthio Fragment as an Adaptive Activating Group

Angewandte Chemie International Edition, Год журнала: 2024, Номер 63(52)

Опубликована: Авг. 29, 2024

Abstract The selective functionalization of carbohydrates holds a central position in synthetic carbohydrate chemistry, driving the ongoing quest for ideal approaches to manipulate these compounds. In this study, we introduce general strategy that enables regiodivergent saccharides. use electron‐deficient photoactive 4‐tetrafluoropyridinylthio (SPyf) fragment as an adaptable activating group, facilitated efficient across all saccharide sites. More importantly, group can be directly installed at C1, C5 and C6 positions biomass‐derived single step site‐selective manner, allowing precision‐oriented modification unprotected saccharides glycans.

Язык: Английский

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Direct Synthesis of Unprotected C-Glycosides via Photoredox Activation of Glycosyl Ester

Organic Letters, Год журнала: 2025, Номер unknown

Опубликована: Янв. 2, 2025

Synthetic C-glycosides play a crucial role in molecular biology and medicine. With the surge of interest demand to provide efforts with sufficient feedstock, it is highly significant pursue novel methodologies access concise efficient manner. Here, we disclose an attractive strategy that diverges itself from conventional multistep reaction sequences involving manipulations protecting groups. Widely available native sugars first react 1,4-dihydropyridine acids via site-selective Mitsunobu reaction, converting them into bench-stable radical precursors. Under visible-light-enabled photoredox catalysis conditions, resulting glycosyl radicals undergo C–C bond formation reactions, yielding variety excellent stereoselectivity. Our method demonstrates good tolerance wide range functional groups has been successfully applied post-transformation drug molecules preparation C-glycosyl amino acids.

Язык: Английский

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Copper-Catalyzed Glycosylation Protocol Based on 1,4-Naphthoquinone-Derived Thioglycosides

Organic Letters, Год журнала: 2025, Номер unknown

Опубликована: Фев. 25, 2025

We report a copper-catalyzed glycosylation protocol utilizing 2-(para-methoxyphenylethynyl)-1,4-naphthoquinone-3-thioglycosides (NQTs) as effective glycosyl donors. These novel donors, characterized by naphthoquinone scaffold, enable rapid and efficient preparation through one-pot, two-step synthesis. Additionally, they are efficiently activated cost-effective Cu(II) salts, facilitating with broad range of substrates. The practicality NQT donors is further demonstrated their compatibility latent-active strategies applicability in the versatile one-pot synthesis saccharides.

Язык: Английский

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C–OH Bond Activation for Stereoselective Radical C-Glycosylation of Native Saccharides

Journal of the American Chemical Society, Год журнала: 2024, Номер 146(47), С. 32269 - 32275

Опубликована: Ноя. 15, 2024

Radical C-glycosylation presents a flexible and efficient method for synthesizing C-glycosides. Existing methods always require multistep processes generating anomeric radicals. In this study, we introduce streamlined approach to produce radicals through direct C-OH bond homolysis of unmodified saccharides, eliminating the need protection, deprotection, or activation steps. These selectively couple with activated alkenes, yielding products high stereoselectivity (>20:1). This is applicable variety native monosaccharides, such as l-arabinose, d-arabinose, d-xylose, l-xylose, d-galactose, β-d-glucose, α-d-glucose, l-ribose, well oligosaccharides including α-lactose, d-(+)-melibiose, acarbose. We also extend amino acid peptide derivatives, demonstrate synthesis an anti-inflammatory agent.

Язык: Английский

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Glycosyl Radical-Based Synthesis of C-Alkyl Glycosides Bearing a Cyclopropane via a Deoxygenative Giese Addition–Reduction–Cyclization Cascade

Organic Letters, Год журнала: 2024, Номер unknown

Опубликована: Дек. 23, 2024

We have developed a glycosyl radical-based synthesis of

Язык: Английский

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