Diversification of Glycosyl Compounds via Glycosyl Radicals

Angewandte Chemie International Edition, Journal Year: 2023, Volume and Issue: 62(38)

Published: June 7, 2023

Glycosyl radical functionalization is one of the central topics in synthetic carbohydrate chemistry. Recent advances metal-catalyzed cross-coupling chemistry and metallaphotoredox catalysis provided powerful platforms for glycosyl diversification. In particular, discovery new precursors conjunction with these advanced reaction technologies have significantly expanded space compound synthesis. this Review, we highlight most recent progress area starting from 2021, reports included will be categorized based on different types better clarity.

Language: Английский

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Desymmetrization–Addition Reaction of Cyclopropenes to Imines via Synergistic Photoredox and Cobalt Catalysis

Journal of the American Chemical Society, Journal Year: 2024, Volume and Issue: 146(28), P. 18892 - 18898

Published: July 5, 2024

Herein, we designed a reaction for the desymmetrization-addition of cyclopropenes to imines by leveraging synergy between photoredox and asymmetric cobalt catalysis. This protocol facilitated synthesis series chiral functionalized cyclopropanes with high yield, enantioselectivity, diastereoselectivity (44 examples, up 93% yield >99% ee). A possible mechanism involving cyclopropene desymmetrization Co-H species imine addition Co-alkyl was proposed. study provides novel route important extends frontier metallaphotoredox

Language: Английский

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Divergent Access to Chiral C2- and C3-Alkylated Pyrrolidines by Catalyst-Tuned Regio- and Enantioselective C(sp³)–C(sp³) Coupling

Journal of the American Chemical Society, Journal Year: 2023, Volume and Issue: 145(28), P. 15456 - 15464

Published: June 12, 2023

Novel-substituted pyrrolidine derivatives are widely used in drugs and bioactive molecules. The efficient synthesis of these valuable skeletons, especially enantiopure derivatives, is still recognized as a key bottleneck to overcome chemical synthesis. Herein, we report highly catalyst-tuned regio- enantioselective hydroalkylation reaction for the divergent chiral C2- C3-alkylated pyrrolidines through desymmetrization readily available 3-pyrrolines. catalytic system consists CoBr2 with modified bisoxazoline (BOX) ligand, which can achieve asymmetric C(sp3)-C(sp3) coupling via distal stereocontrol, providing series high efficiency. Moreover, nickel allows synthesize C2-alkylated tandem alkene isomerization/hydroalkylation reaction. This method uses catalysts, BOX ligands, reagents, delivering enantioenriched 2-/3-alkyl substituted excellent enantioselectivity (up 97% ee). We also demonstrate compatibility this transformation complex substrates derived from molecules good efficiency, offers distinct entry more functionalized N-heterocycles.

Language: Английский

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Diverse Synthesis of C-Glycosides by Stereoselective Ni-Catalyzed Carboboration of Glycals

Journal of the American Chemical Society, Journal Year: 2024, Volume and Issue: 146(28), P. 18866 - 18872

Published: July 5, 2024

C-Glycosides are important structures that common to natural products and pharmaceutical agents. Established methods for their synthesis involve the reaction of an activated anomeric carbon. In this study, we report a conceptually new approach involves stereoselective Ni-catalyzed carboboration glycals. these reactions, not only is C–C bond formed at carbon, but synthetically useful C–B also installed. Upon oxidation, differentially protected C-glycosides be formed. addition, stereospecific manipulation leads diverse C-glycosides. Finally, application method in established C-glycosides, such as C-glycosyl amino acids, well strategy make all possible diastereomers C1 C2.

Language: Английский

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Base‐Promoted Glycosylation Allows Protecting Group‐Free and Stereoselective O‐Glycosylation of Carboxylic Acids**

Angewandte Chemie International Edition, Journal Year: 2023, Volume and Issue: 62(42)

Published: Aug. 17, 2023

Here we report a simple and general method to achieve fully unprotected, stereoselective glycosylation of carboxylic acids, employing bench-stable allyl glycosyl sulfones as donors. Running the reaction under basic conditions was crucial for efficiencies selectivities. Both donor activation stage glycosidic bond forming process are compatible with free hydroxyl groups, thereby allowing use unprotected This transformation is stereoconvergent, occurs mild metal-free at ambient temperature visible light (455 nm) irradiation, displays remarkable scope respect both partners. Many natural products commercial drugs, including an acid derived from complex anticancer agent taxol, were efficiently glycosylated. Experimental studies provide insights into origin stereochemical outcome.

Language: Английский

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Cobalt‐Catalyzed Hydroalkylation of Alkenes and Alkynes: Advantages and Opportunities

ChemCatChem, Journal Year: 2023, Volume and Issue: 16(1)

Published: Nov. 3, 2023

Abstract Sp3‐hybridized carbons‐rich molecules play a crucial role in drug discovery. Cobalt‐catalyzed hydroalkylation of alkenes and alkynes is an efficient method to synthesize these compounds. These reactions exhibit wide range applicability high tolerance for functional groups, utilizing readily available instead hyperactive metallic reagents. Herein, we summarize the advancements cobalt‐catalyzed alkynes, according different reaction mechanisms. We present detailed discussion scope limitations, plausible mechanisms opportunities further development.

Language: Английский

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Direct Construction of C‐Alkyl Glycosides from Non‐Activated Olefins via Nickel‐Catalyzed C(sp³)─C(sp³) Coupling Reaction

Advanced Science, Journal Year: 2024, Volume and Issue: 11(12)

Published: Jan. 18, 2024

Among C-glycosides, C-alkyl glycosides are significant building blocks for natural products and glycopeptides. However, research on efficient construction methods remains relatively limited. Compared with Michael acceptors, non-activated olefins more challenging substrates have rarely been employed in the of C-glycosides. Here, a highly convenient approach synthesis through nickel-catalyzed C(sp

Language: Английский

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CoH-catalyzed asymmetric remote hydroalkylation of heterocyclic alkenes: a rapid approach to chiral five-membered S- and O-heterocycles

Chemical Science, Journal Year: 2024, Volume and Issue: 15(23), P. 8888 - 8895

Published: Jan. 1, 2024

A highly efficient method achieves precise construction of alkyl chiral centers at remote C3-positions in five-membered S/O-heterocycles via cobalt-catalyzed asymmetric hydroalkylation heterocyclic alkenes.

Language: Английский

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Stereoselective Construction of Multifunctional C-Glycosides Enabled by Nickel-Catalyzed Tandem Borylation/Glycosylation

Journal of the American Chemical Society, Journal Year: 2024, Volume and Issue: 146(32), P. 22413 - 22423

Published: Aug. 3, 2024

Stereochemically pure saccharides have indispensable roles in fields ranging from medicinal chemistry to materials science and organic synthesis. However, the development of a simple, stereoselective, efficient glycosylation protocol access α- β-C-glycosides (particularly 2-deoxy entities) remains persistent challenge. Existing studies primarily focused on C1 modification carbohydrates transformation glycosyl radical precursors. Here, we innovate by harnessing situ generated glycosyl-Ni species achieve one-pot borylation cascade manner, which is enabled an earth-abundant nickel-catalyzed carboboration readily accessible glycals without any ligand. This work reveals potential for modular multifunctional platform facilitate simultaneous introduction C-C C-B bonds at stereogenic center saccharides, largely unexploited research area. Preliminary experimental computational indicate that endocyclic O C3 group play important stereoseclectively forging glycosidic bonds. As result, diverse range C-R (R = alkyl, aryl, alkenyl) 2-deoxygenated glycosides bearing modifiable boron groups could be rapidly made with excellent stereocontrol exhibit remarkable functional tolerance. The synthetic underscored late-stage natural products commercial drugs as well facile preparation various rare sugars, bioactive conjugates, key intermediates prorocentin, phomonol, aspergillide A.

Language: Английский

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Enantio- and Diastereoselective Synthesis of P-Stereogenic Phospholane Oxides via Cobalt-Catalyzed Hydroalkylation

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

Published: April 10, 2025

Chiral phospholane ligands and catalysts have been widely applied in asymmetric catalysis synthesis. However, the construction of chiral skeleton remains challenging primarily relies on use auxiliaries or resolution. In this work, a highly enantioselective diastereoselective synthesis P-stereogenic oxides has achieved through cobalt-catalyzed desymmetric hydroalkylation strategy. This method enables two discrete stereocenters with excellent yields enantiomeric excesses.

Language: Английский

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