71 research outputs found
Essential oils in plant protection and postharvest control of Colletotrichum acutatum (Mycology, plant protection, essential oils)
C-Glycosyl styrene type compounds by Pd-catalyzed cross-coupling reactions of anhydro-aldose tosylhydrazones with benzyl bromides
LBL
Thio-click approach to the synthesis of stable glycomimetics
Carbon-sulfur-bridged glycomimetics were prepared by free radical hydrothiolation of the exocyclic
double bond of unsaturated sugars. Reaction between benzoyl-substituted pyranoid-exoglycal
and a range of thiols including peptide, 1-thioglycerol and 1-thiosugar derivatives gave β-Dconfigured
carbon-sulfur-linked glycoconjugates with full stereoselectivity. Addition of a panel of
thiols to a 3-exomethylene-glucofuranose derivative also proceeded in a stereoselective manner and
afforded a series of D-allo-configured 3-deoxy-3-C-S-bridged glycoconjugates
Synthesis of 2-(β-D-glucopyranosyl)-5-(substituted-amino)-1,3,4-oxa-and -thiadiazoles for the inhibition of glycogen phosphorylase
Synthesis of 2-(β-D-glucopyranosylamino)-5-substituted-1,3,4-oxadiazoles for inhibition of glycogen phosphorylase
Pd-catalyzed coupling reactions of anhydro-aldose tosylhydrazones with aryl bromides to produce substituted exo-glycals
K
Stereoselective Synthesis of Carbon-Sulfur-Bridged Glycomimetics by Photoinitiated Thiol-Ene Coupling Reactions
Oligosaccharides and glycoconjugates are abundant in all living organisms, taking part in a
multitude of biological processes. The application of natural O-glycosides in biological studies and
drug development is limited by their sensitivity to enzymatic hydrolysis. This issue made it necessary
to design hydrolytically stable carbohydrate mimetics, where sulfur, carbon, or longer interglycosidic
connections comprising two or three atoms replace the glycosidic oxygen. However, the formation
of the interglycosidic linkages between the sugar residues in high diastereoslectivity poses a major
challenge. Here, we report on stereoselective synthesis of carbon-sulfur-bridged disaccharide
mimetics by the free radical addition of carbohydrate thiols onto the exo-cyclic double bond of
unsaturated sugars. A systematic study on UV-light initiated radical mediated hydrothiolation
reactions of enoses bearing an exocyclic double bond at C1, C2, C3, C4, C5, and C6 positions
of the pyranosyl ring with various sugar thiols was performed. The e�ect of temperature and
structural variations of the alkenes and thiols on the e�cacy and stereoselectivity of the reactions
was systematically studied and optimized. The reactions proceeded with high e�cacy and, in most
cases, with complete diastereoselectivity producing a broad array of disaccharide mimetics coupling
through an equatorially oriented methylensulfide bridge
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