Cyclization in situ of enose-/ynose-nitrilimines: an expedient approach to the synthesis of chiral glycopyrazoles and pyrazolonucleosides

Roy, A. K.; Sahabuddin, Sk.; Achari, Basudeb; Mandal, Sukhendu

doi:10.1016/j.tet.2004.10.096

Cited by 13 publications

(6 citation statements)

References 31 publications

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“…Reaction of the THF-methoxy acetal 4a with allyl trimethylsilane and trimethylsilyl triflate (TMSOTf) 12 gave the allyl substituted THF 28a as a 2.3:1 mixture of diastereoisomers in 95% yield. The nucleoside analog 28b was prepared in 61% yield as 2.9:1 mixture of diastereoisomers by reaction with 2,4-bis-(trimethylsilyloxy)pyrimidine 13 and TMSOTf in CH 3 CN. Surprisingly, attempted addition of the silyl ketene acetal [CH 2 =C(OTBS)(OEt)] 14 to the methoxy acetal 4a or acetoxy acetal 9a failed and only the THF-vinyl phosphonate 12, resulting from reduction of the oxacarbenium ion, was observed.…”

Section: Resultsmentioning

confidence: 99%

Trapping hemiacetals with phosphono substituted palladium π-allyl complexes for the synthesis of substituted cyclic ethers

Sutivisedsak

Dawadi

Spilling

2015

Tetrahedron Letters

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Oxidation of hydroxy substituted phosphono allylic carbonates gave the aldehyde substituted phosphonates in good yield. Stereospecific palladium (0)-catalyzed cyclization in the presence of methanol or water gave acetal tetrahydrofuran and tetrahydropyran vinyl phosphonate products derived from hemiacetal trapping. The tetrahydrofuran acetals undergo Lewis acid catalyzed addition of nucleophiles to give diastereoisomeric mixtures of substituted tetrahydrofurans.

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Section: Resultsmentioning

confidence: 99%

Trapping hemiacetals with phosphono substituted palladium π-allyl complexes for the synthesis of substituted cyclic ethers

Sutivisedsak

Dawadi

Spilling

2015

Tetrahedron Letters

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“…The fluorescence spectra were measured in a 10 mm path length quartz cuvette using a Perkin–Elmer LS55 luminescence spectrometer. Glucose derivative 4 ,15 monomer 6 16 and 7 17 were prepared according to reported methods, respectively.…”

Section: Methodsmentioning

confidence: 99%

Prepolymerization and postpolymerization functionalization approaches to fluorescent conjugated carbazole‐based glycopolymers via “click chemistry”

Chen

Han

2009

J. Polym. Sci. A Polym. Chem.

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Facile prepolymerization and postpolymerization functionalization approaches to prepare well‐defined fluorescent conjugated glycopolymers through Cu(I)‐catalyzed azide/alkyne “Click” ligation were explored. Two well‐defined carbazole‐based fluorescent conjugated glycopolymers were readily synthesized based on these strategies and characterized by 1H NMR, 13C NMR, IR spectra, and UV‐vis spectra. The “Click” ligation offers a very effective conjugation method to covalently attach carbohydrate residues to fluorescent conjugated polymers. In addition, the studies of carbohydrate–lectin interactions were performed by titration of concanavalin A (Con A) to D‐glucose‐bearing poly(anthracene‐alt‐carbazole) copolymer P‐2 resulting in significant fluorescence quenching of the polymer due to carbohydrate–lectin interactions. When peanut agglutinin (PNA) was added, no distinct change in the fluorescent properties of P‐2 was observed. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 2948–2957, 2009

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“…These 1,3-dipoles are typically generated by dehydroha- [190] or with (diacetoxy)iodobenzene [191,192].…”

Section: Synthesis Of Pyrazoles and Indazoles J667mentioning

confidence: 99%

Five‐Membered Heterocycles: 1,2‐Azoles. Part 1. Pyrazoles

Elguero

Silva

Tomé

2011

Modern Heterocyclic Chemistry

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Cyclization in situ of enose-/ynose-nitrilimines: an expedient approach to the synthesis of chiral glycopyrazoles and pyrazolonucleosides

Cited by 13 publications

References 31 publications

Trapping hemiacetals with phosphono substituted palladium π-allyl complexes for the synthesis of substituted cyclic ethers

Trapping hemiacetals with phosphono substituted palladium π-allyl complexes for the synthesis of substituted cyclic ethers

Prepolymerization and postpolymerization functionalization approaches to fluorescent conjugated carbazole‐based glycopolymers via “click chemistry”

Five‐Membered Heterocycles: 1,2‐Azoles. Part 1. Pyrazoles

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