Cycloaddition Reactions in Carbohydrate Chemistry

Giuliano, Robert M.

doi:10.1021/bk-1992-0494.ch001

Cited by 16 publications

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“…The stereodifferentiating characteristics of the Diels−Alder reaction can be profitably enhanced if cycloadditions are performed on chiral precursors or with chiral catalysts. In this context, carbohydrate-based cycloadditions represent an attractive and emerging approach in organic synthesis . This strategy combines the powerful stereoselection provided by a cycloadditive process along with the stereodirecting effect of an appropriate sugar template.…”

Section: Introductionmentioning

confidence: 99%

Hetero-Diels−Alder Reactions of Homochiral 1,2-Diaza-1,3-butadienes with Diethyl Azodicarboxylate under Microwave Irradiation. Theoretical Rationale of the Stereochemical Outcome

et al. 1999

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The stereoselective normal electron demand Diels-Alder reactions of chiral 1,2-diaza-1,3-butadienes, derived from acyclic carbohydrates having different configurations (1-6), with diethyl azodicarboxylate (DEAD) are disclosed. Reactions proceed slowly in benzene solution at room temperature, but are greatly accelerated by microwave irradiation to form the corresponding functionalized 1,2,3,6-tetrahydro-1,2,3,4-tetrazines (7-18) in good yields. The observed stereoselectivity is markedly dependent on the relative stereochemistry at C-1′,2′. Thus, 1,2-diazoalkenes derived from per-Oacylated sugars having threo configuration at C-1′,2′ give tetrazines with a high facial selectivity, whereas those having erythro configuration at C-1′,2′ afford products in lower diastereomeric ratios. The facial diastereoselection has been rationalized by a PM3 computational study. These results prove that in the transition structures (TSs) the reacting azoalkene exhibits formal negative charges at C-3 and N-2, the former being of greater magnitude, while the heterodienophile displays a partial positive charge at the substituent attached to the nitrogen atom. Accordingly, a stabilizing electrostatic interaction will only occur in TSs involving an endo orientation of the azodicarboxylate in its approach to the azadiene, a fact consistent with the experimental observations.

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Section: Introductionmentioning

confidence: 99%

Hetero-Diels−Alder Reactions of Homochiral 1,2-Diaza-1,3-butadienes with Diethyl Azodicarboxylate under Microwave Irradiation. Theoretical Rationale of the Stereochemical Outcome

et al. 1999

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“…Nitrile oxide cycloaddition with olefin represents an easy route to this type of heterocycle [8,9]. Reactivity of carbohydrate-derived olefins has been tested in this type of cycloadditions [10][11][12][13]. In the present chapter, we aim to summarize and discuss reports of these cycloadditions on sugar olefins, with a focus on exo-methylene sugars or activated exo-glycals, leading with high regio-and stereocontrol to saccharidic spiro-isoxazoli(di)nes.…”

Section: Introductionmentioning

confidence: 99%

Cycloaddition Reactions of Sugar-Based Olefins, Nitrones and Nitrile Oxides: En Route to Saccharidic Spiroisoxazoli(di)nes

Pellegrini‐Moise

Richard

2019

Topics in Heterocyclic Chemistry

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Isoxazoline and isoxazolidine-containing compounds are privileged structures of interest, notably in synthetic and medicinal chemistry. These heterocycles can be obtained by 1,3dipolar cycloaddition reactions between an olefin and a nitrile oxide or a nitrone. This reaction generates the formation of one C-C and one C-O bond and up to three chiral centers in one step. In the present chapter, we aim to summarize and discuss reports of these cycloadditions on sugar olefins, with a focus on exo-methylene sugars or activated exoglycals, leading with high regio-and stereocontrol to saccharidic spiroisoxazoli(di)nes. Additional examples of cycloaddition reactions involving chiral nitrone, sugar nitrile oxide, sugar nitrone and also two chiral sugar partners will also be discussed. Due to the importance of the spiro structure in several biologically active compounds, these spiroheterocycles can be regarded as spironucleoside analogues, mimics of natural building blocks or multicyclic sugar scaffolds suitable for selective derivatization. Some of them thus showed promising biological properties as antibacterial agents or enzyme inhibitors. Moreover, the labile nature of the N−O bond in the isoxazolidine ring makes it an attractive target for synthetic chemists. The reactivity of this scaffold has therefore been widely studied and the cycloadducts have been converted to other classes of compounds of interest. Examples of the biological relevance and synthetic use and reactivity of these spiro-sugars will be given in this chapter.

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“…These heterocycles exhibit antibacterial and antifungal activities (17). Isoxazolidines derived from carbohydrate based nitrones are potential intermediates for the synthesis of various aza sugars, on account of the presence of amino group in the masked form (19)(20)(21)(22)(23). Isoxazolidines derived from carbohydrate based nitrones are potential intermediates for the synthesis of various aza sugars, on account of the presence of amino group in the masked form (19)(20)(21)(22)(23).…”

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confidence: 99%

“…Regioselective nitrone cycloaddition, followed by reduction of the N-O bond to produce both amino and hydroxyl functions, allows the synthesis of compounds of many potential interests (1,18). Isoxazolidines derived from carbohydrate based nitrones are potential intermediates for the synthesis of various aza sugars, on account of the presence of amino group in the masked form (19)(20)(21)(22)(23). As a consequence, reports of nitrone cycloaddition continue to emerge in the literature using carbohydrates as a precursor, Shing et al (24) reported stereo-and regioselectivity in intramolecular nitrone-alkene cycloaddition of hept-6-enose derived from carbohydrates.…”

mentioning

confidence: 99%

Antibacterial Activity, Quantitative Structure–Activity Relationship and Diastereoselective Synthesis of Isoxazolidine Derivatives Via 1,3‐Dipolar Cycloaddition of d‐glucose Derived Nitrone with Olefin

et al. 2009

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The diastereoselectivity of the intermolecular 1,3-dipolar cycloaddition reaction of d-glucose-derived nitrones with both cyclic and acyclic dipolarophiles were studied. The reaction of nitrone with acyclic dipolarophiles resulted in the formation of the endo adduct exclusively whereas with cyclic dipolarophiles endo adduct was obtained as the major product. Antibacterial activity was evaluated for these eighteen isoxazolidine derivatives against Staphylococcus aureus NCIM5021, Escherichia coli NCIM 2931 and Pseudomonas aeruginosa NCIM 5029 by twofold dilution technique using resazurin as the indicator dye. Quantitative structureactivity relationships were developed with fourteen and the model was validated with four data. Electronic and spatial descriptors were the major contributors in all the three quantitative structureactivity relationship equations and the statistical parameters r(2), r(2)(adj) , F-ratio and q(2) were found to be satisfactory.

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Cycloaddition Reactions in Carbohydrate Chemistry

Cited by 16 publications

References 0 publications

Hetero-Diels−Alder Reactions of Homochiral 1,2-Diaza-1,3-butadienes with Diethyl Azodicarboxylate under Microwave Irradiation. Theoretical Rationale of the Stereochemical Outcome

Hetero-Diels−Alder Reactions of Homochiral 1,2-Diaza-1,3-butadienes with Diethyl Azodicarboxylate under Microwave Irradiation. Theoretical Rationale of the Stereochemical Outcome

Cycloaddition Reactions of Sugar-Based Olefins, Nitrones and Nitrile Oxides: En Route to Saccharidic Spiroisoxazoli(di)nes

Antibacterial Activity, Quantitative Structure–Activity Relationship and Diastereoselective Synthesis of Isoxazolidine Derivatives Via 1,3‐Dipolar Cycloaddition of d‐glucose Derived Nitrone with Olefin

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