Radical Pathway Glycosylation Empowered by Bench-Stable Glycosyl Donors

Accounts of Chemical Research, Journal Year: 2023, Volume and Issue: 56(18), P. 2473 - 2488

Published: Aug. 18, 2023

ConspectusThe study of carbohydrates has emerged as a crucial research area in various disciplines due to their pivotal roles cellular processes. To facilitate in-depth exploration biological functions, chemical glycosylation reactions that allow facile access glycoconjugates broad community are highly needed. In classical reactions, glycosyl donor is activated by an acid generate reactive electrophilic intermediate, which subsequently forms glycosidic bond upon reaction with nucleophilic acceptor. Such ionic pathway been the mainstay technique for glycoconjugate synthesis and allowed numerous intricate structures. Nevertheless, limitations still exist. For instance, when labile donors or harsh activating conditions required, these methods show limited tolerance hydroxyl groups abundant on sugar rings. addition, achieving good stereocontrol represents another longstanding obstacle. recent years, new modes activation have sought tackle above challenges.We noted passing through intermediacy radicals via cascade single-electron transfer steps possess significant but underexplored potential. Progress this slow large part dearth handy maneuver radicals. Most existing call either forcing unstable/inconvenient starting materials. order better exploit power radical glycosylation, we developed range donors─namely, sulfoxides, sulfones, sulfinates─that bench stable can be readily prepared from simple These form under mild conditions. Enabled use donors, series could used making O-, S-, C-glycosides, some were previously difficult access. many cases, no protecting group required. As illustration potential utility, our adopted preparation sugar–drug conjugates, sugar–DNA glycopeptides, even glycoproteins. While most cases intrinsic reactivity intermediates explored axially configured products, also utilization external, delicate reagents, catalysts override such innate preference achieve catalyst-controlled stereoselectivity.We believe enormous inspire development novel glycoside synthesis. Account, highlight design principles summarize advancements enabled use, provide outlook future directions field.

Language: Английский

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Transformations of carbohydrate derivatives enabled by photocatalysis and visible light photochemistry

Chemical Science, Journal Year: 2024, Volume and Issue: 15(4), P. 1204 - 1236

Published: Jan. 1, 2024

This review article highlights the diverse ways in which recent developments areas of photocatalysis and visible light photochemistry are impacting synthetic carbohydrate chemistry.

Language: Английский

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

Organic Letters, Journal Year: 2025, Volume and Issue: unknown

Published: Jan. 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.

Language: Английский

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Radical C‐Glycosylation Using Photoexcitable Unprotected Glycosyl Borate

Chemistry - A European Journal, Journal Year: 2024, Volume and Issue: unknown

Published: Aug. 23, 2024

Abstract We have developed radical C‐glycosylation using photoexcitable unprotected glycosyl borate. The direct excitation of borate under visible light irradiation enabled the generation anomeric without any photoredox catalysts. in situ generated was applicable to addition such as Giese‐type and Minisci‐type reaction introduce alkyl heteroaryl groups at position. In addition, radical–radical coupling between acyl imidazolide provided C‐glycosides.

Language: Английский

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Recent Advances in Organic Photocatalyst‐Promoted Carbohydrate Synthesis and Modification under Light Irradiation

Chemistry - An Asian Journal, Journal Year: 2025, Volume and Issue: unknown

Published: Jan. 2, 2025

Abstract Photoredox catalysis has been developed as a sustainable and eco‐friendly catalytic strategy, which might provide innovative solutions to solve the current synthetic challenges barriers in carbohydrate chemistry. During last few decades, study of organic photocatalyst‐promoted synthesis modification received significant attention, provides an excellent inexpensive metal‐free alternative photoredox well introduces new fastest‐growing era access complex carbohydrates simply. In this review, we aim overview under light irradiation, is expected directions for further investigation.

Language: Английский

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One step aqueous synthesis of unprotected glycosyl C-sulfonates

Carbohydrate Research, Journal Year: 2025, Volume and Issue: 551, P. 109411 - 109411

Published: Feb. 1, 2025

Language: Английский

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Synthesis of an Angular Triquinane Structure Based on a Stereoselective Decarboxylative Giese Reaction at an Angular Position in a Diquinane Skeleton

Tetrahedron, Journal Year: 2025, Volume and Issue: unknown, P. 134612 - 134612

Published: March 1, 2025

Language: Английский

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One‐Step Aqueous Synthesis of Glycosyl Pyridinium Salts, Electrochemical Study, and Assessment of Utility as Precursors of Glycosyl Radicals Using Photoredox Catalysis

ChemistryOpen, Journal Year: 2025, Volume and Issue: unknown

Published: April 21, 2025

A single step method for the production of unprotected glycosyl pyridinium salts has been developed involving treatment sugar with a pyridine, triethylamine, and either 2‐chloro‐1,3‐dimethylimidazolinium chloride (DMC) or 2‐chloro‐1,3‐dimethyl‐1 H‐benzimidazol‐3‐ium (CDMBI) as an activator, in aqueous solution. Reaction efficiency is sensitive to steric effects, particular, ortho ‐substitution pyridine ring significantly decreased conversion product; para well tolerated. Cyclic voltammetry reveals that possess reduction potentials range −0.9 −1.4 V versus standard calomel electrode, which are modulated by electron effects substituents. However, pyridiniums not found be useful precursors radicals under photoredox conditions.

Language: Английский

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Photoinduced Diastereoselective and Stereodivergent Synthesis of C-Styryl Glycosides

Organic Letters, Journal Year: 2025, Volume and Issue: unknown

Published: May 16, 2025

A novel and efficient method for the stereoselective stereodivergent synthesis of both unprotected protected styryl C-glycosides through reaction sodium glycosyl sulfinate hypervalent iodine reagents is described. Using 2-bromo-9-fluorenone as a photocatalyst, C-styryl glycosides with an E configuration were selectively obtained. Furthermore, introduction newly designed iridium-based catalyst enabled selective formation predominantly in Z configuration. Mechanistic studies reveal radical involved transformation.

Language: Английский

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Emerging Advances of the Radical Pathway Glycosylation Enabled by Bench‐Stable Glycosyl Donors: Glycosyl Sulfoxides, Glycosyl Sulfones, and Glycosyl Sulfinates

Advanced Synthesis & Catalysis, Journal Year: 2024, Volume and Issue: 366(19), P. 4017 - 4041

Published: July 30, 2024

Abstract In synthetic carbohydrate chemistry, the modification of glycosyl radicals pathway stands as a central area focus. The radical‐based reactions often demonstrate remarkable compatibility with various functional groups owing to mild initiation conditions. particular, identification novel radical precursors, combined advanced reaction techniques, has substantially broadened scope compound synthesis. Despite presence versatile donors, synthesis noble donors is still addressed need and challenges associated sugar chemistry. Currently, new class precursors been developed which enables production C ‐, S O N ‐glycosides efficiently. this light, we highlight strategies towards bench‐stable sulfoxides, sulphone, sulfite that can enable site‐, regio‐ stereoselective transformation protected or naked synthons in Here, review article covers recent developments selective diversification such alkylation, arylation, alkenylation, sulfuration, C−H activation, DNA conjugation via along mechanistic aspects, challenges, future directions.

Language: Английский

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