2-Deoxy-β-glycosides are essential components of natural products and pharmaceuticals; however, the corresponding 2-deoxy-β-glycosidic bonds challenging to chemically construct. Herein, we describe an efficient catalytic protocol for synthesizing 2-deoxy-β-glycosides via either IPrAuNTf2-catalyzed activation a unique 1,2-trans-positioned C2-S-propargyl xanthate (OSPX) leaving group or (PhO)3PAuNTf2-catalyzed 1,2-trans-C2-ortho-alkynylbenzoate (OABz) substituent thioglycosides. These...

A mild and convenient method for the synthesis of reverse glycosyl fluorides (RGFs) has been developed that is based on silver-promoted radical dehydroxymethylative fluorination carbohydrates. salient feature reaction furanoid pyranoid carbohydrates furnish structurally diverse RGFs bearing a wide variety functional groups in good to excellent yields. Intramolecular hydrogen atom transfer experiments revealed involves an underexploited proceeds via β-fragmentation sugar-derived primary...

We demonstrate an efficient, scalable, and stereoselective C-glycosylation with thioglycosides possessing a unique photoactive tetrafluoropyridin-4-yl (TFPy) thio radical leaving group, affording editable medicinally biologically essential C-α-glucogallin derivatives. In the presence of silyl enol ether acceptors, desulfurative coupling reaction performs smoothly under mild conditions upon exposure to blue light irradiation. This versatile protocol permits synthesis sugar-drug chimeras by C1...

A mild and convenient protocol for direct synthesis of β-mannosides has been developed. Glycosylation 4,6-O-benzylidene-protected mannosyl ortho-hexynylbenzoates with various alcohol acceptors catalyzed by gold(I) complex proceeded smoothly at 0 °C to room temperature afforded the corresponding β-mannoside in high yield satisfactory stereoselectivity. This reaction was applied total acremomannolipin its analogue.

A convenient and efficient protocol for the synthesis of 6-alkyl phenanthridines 1-alkyl isoquinolines has been developed. The reaction relies on coupling 2-isocyanobiphenyls vinyl isonitriles with alkyl radicals formed by silver-catalyzed decarboxylation stoichiometric aliphatic carboxylic acids, affords diverse phenanthridine isoquinoline derivatives under mild conditions. experiment β-scission cyclobutylcarbinyl is used to shed light mechanism.

We have developed an efficient protocol for the synthesis of C-glycosylated phenanthridines. Tetrafuranos-4-yl and pentapyranos-5-yl radicals, generated from K2S2O8-mediated oxidative decarboxylation furan- pyranuronic acids, undergo attack to 2-isocyanodiphenyls ensuing homolytic aromatic substitution provide diverse phenanthridines in satisfactory yields without resort transition metals. This reaction tolerates various functional groups, enables ready complex oligosaccharide-based The...

Campylobacter jejuni is the leading cause of human diarrheal diseases and has been designated as one highly resistant pathogens by World Health Organization. The C. capsular polysaccharides feature broad existence uncommon 6dHepp residues have proven to be potential antigens develop innovative antibacterial glycoconjugation vaccines. To address lack synthetic methods for rare architectures importance, we herein describe a novel efficient approach preparation d-/l-6dHepp fluorides that power...

The radical decarboxylative azidation of structurally diverse uronic acids has been established as an efficient approach to reverse glycosyl azides and rare sugar-derived under the action Ag2CO3, 3-pyridinesulfonyl azide, K2S2O8. power this method highlighted by divergent synthesis 4'-C-azidonucleosides using Vorbrüggen glycosylation nucleobases with 4-C-azidofuranosyl acetates. antiviral assessment resulting nucleosides revealed one compound a potential inhibitor covalently closed circular DNA.

Four new Stemona alkaloids, sessilistemonamines A-C (1-3, resp.) and dihydrostemoninine (4), were isolated from the roots of sessilifolia. Their structures relative configurations elucidated by means in-depth 1D- 2D-NMR-spectroscopic as well mass-spectrometric experiments; structure 4 was solved X-ray single-crystal diffraction. The stereoisomeric compounds 1-3 share an unprecedented tetracyclic decahydro-1H-furo[2',3':4,5]cyclopenta[1,2-b]pyrrolo[1,2-a]azepine nucleus. Compounds 1 2 found...

An efficient protocol for synthesizing reverse glycosyl fluorides is described, relying on silver-promoted decarboxylative fluorination of structurally diverse pentofuran- and hexopyranuronic acids under the mild reaction conditions. The potential applications are further demonstrated by converting readily available d-uronic acid derivatives into uncommon d-/l-glycosyl through a C1-to-C5 switch strategy. mechanism corroborated 5-exo-trig radical cyclization allyl α-d-C-glucopyranuronic...

(C₆F₅)₃B·(HF)_n-catalyzed glycosylation of disarmed glycosyl fluorides and reverse with structurally diverse nucleophiles has been achieved.

Comprehensive Summary A direct oxidative radical decarboxylative cyanomethylation of carboxylic acids is described using 3‐azido‐2‐methylbut‐3‐en‐2‐ol as the carbon‐centered acceptor. The transformation applicable to structurally diverse α ‐amino acids, ‐oxy ‐keto pentofuranuronic and hexopyranuronic acids. mechanistic investigations suggest that a process involved in transformation. This work provides potential approach β acid, 5‐deoxy‐hexofuranose, 6‐deoxy‐heptose constructs biological relevance.

Convenient synthesis of an N-glycan octasaccharide (A) the bisecting type was described. The stable and easily prepared orthoester F, 3′′-O-chloroacetyl-4′′,6′′-O-benzylidene-α-d-glucopyranose 1′′,2′′-(chloromethyl 3′,6′-di-O-benzyl-2′-deoxy-2′-phthalimido-β-d-glucopyranosyl-(1→4)-3,6-di-O-benzyl-2-deoxy-2-phthalimido-β-d-glucopyranosylazide-4′-yl orthoacetate), designed as key intermediate with two advantages: (1) distinguishing OH-2′′ from OH-3′′ in β-d-glucopyranoside to construct central...

2-Deoxy-glycosides are monosaccharides in which the hydroxyl group at C-2 is replaced with a hydrogen atom.They exist widely natural products and show various bioactivity.The recent advances organic synthesis of 2-deoxy-glycosides summarized mainly focusing on direct etherification, glycosidic bond formation, temporary protecting groups, from non-sugar so on.

An efficient protocol to construct β-d-gluco-/galactosaminosyl linkages was established using nonparticipating and strong electron-withdrawing C-2-2,4-dinitrobenzenesulfonamide (DNsNH)-directed SN2-like glycosylation of glycosyl ortho-hexynylbenzoates. The reaction is applicable a wide range O-, N-, C-nucleophiles features convenient conversion DNsNH into AcNH in high yield under mild conditions. Oligomerization-ready trisaccharide, composed β-d-(1→3)-glucosamino residues, has been achieved,...

An efficient protocol has been established for β-glycosylations with 2-deoxy-2-(2,4-dinitrobenzenesulfonyl)amino (2dDNsNH)-glucopyranosyl/galactopyranosyl selenoglycosides using PhSeCl/AgOTf as an activating system. The reaction features highly β-selective glycosylation a wide range of alcohol acceptors that are either sterically hindered or poorly nucleophilic. Thioglycoside- and selenoglycoside-based alcohols prove to be viable nucleophiles, opening up new opportunities one-pot...

Abstract An effective and stereoselective protocol for convergent synthesis of solamargine, a representative spirosolane‐type glycoalkaloids, is reported. HB(C 6 F 5 ) 4 ‐catalyzed coupling 26‐azido‐pseudodiosgenin with chacotriosyl trichloroacetimidate as the key step solamargine proceeded in high yield excellent stereoselectivity. Three analogues were synthesized by method. Protonation nitrogen atom deuterium chloride had significant influence on 1 H NMR spectrum solamargine. On basis...

An efficient, convenient protocol for the preparation of per-O-acetylated p-tolylthio glycosides is described. Treatment various unprotected sugars, including 2-deoxy-2-amino sialic acid, lactose, and maltose, with acetic anhydride using SnCl4 as a catalyst, subsequently p-tolylthiol, furnished corresponding thioglycosides in 71%–90% yield under solvent-free conditions.

An efficient protocol for the synthesis of diverse diosgen-3-yl glycoconjugates, a class novel synthetic analogs natural saponins biological significance, has been developed. The method relies on gold(I)-catalyzed etherification ortho-hexynylbenzoate with stoichiometric sugar alcohols to afford corresponding glycoconjugates in 38%-99% yields. reaction involves preferential attack hydroxyl groups C3 position homoallylic carbocation intermediate and displays broad substrate scope good...