A series of novel mono-1,2,3-triazole and bis-1,2,3-triazole acyclonucleoside analogues of 9-(4-hydroxybutyl)guanine was prepared via copper(I)-catalyzed 1,3-dipolar cycloaddition of N-9 propargylpurine, N-1-propargylpyrimidines/as-triazine with the azido-pseudo-sugar 4-azidobutylacetate under solvent-free microwave conditions, followed by treatment with K(2)CO(3)/MeOH, or NH(3)/MeOH. All compo...

Total syntheses of (+)-nankakurine A (2) and (+)-nankakurine B (3) were accomplished by a sequence that employs an intramolecular dipolar cycloaddition of an azomethine imine intermediate to form the azatricyclic moiety and establish the relative configuration of the spiropiperidine ring. These syntheses, together with the synthesis of the originally purported structure 1 of nankakurine A, rigo...

A chemical library of 1,2,3-triazole fused carbohydrate mimetics was constructed. To synthesize enantiomerically pure mimetics, we developed a stereo- or diastereodivergent synthetic route from D-glucose, D-mannose and D-galactose as chiral sources. In this synthesis, an In(OTf)(3)-catalyzed tandem azidation-1,3-dipolar cycloaddition reaction of 1,1-dimethoxyhex-5-yne derivatives with TMSN(3) w...

A facile synthesis of dispirooxindolopyrrolidines has been accomplished via a one-pot three component 1,3-dipolar cycloaddition reaction. The reaction of azomethine ylides generated in situ from L-phenylalanine and substituted isatins with a series of unusual (E)-2-oxoindolino-3-ylidene acetophenone dipolarophiles in the ionic liquid 1-butyl-3-methylimidazolium bromide [bmim]BF4, furnished the ...

Benzonitrile oxide (la) reach with 1,1,2,2,3,3-hexamethyl-4,5-bis(methylene)cyclopen~e (5) to give a mixture of the 1,3-dipolar cycloaddition product 8 and the oxime 9. This reaction is 26 times slower than the corresponding reaction of la with 1,2-bis(methylene)cyclopentane (15), which exclusively yields the 2-isoxazoline 19. With the assumption that the oxime 9 is generated by a stepwise proc...

Few-layer graphenes (FLG) produced by dispersion and exfoliation of graphite in N-methylpyrrolidone were successfully functionalized using the 1,3-dipolar cycloaddition of azomethine ylides. The amino functional groups attached to graphene sheets were quantified by the Kaiser test. These amino groups selectively bind to gold nanorods, which were introduced as contrast markers for the identifica...

A highly regio- and stereoselective synthesis of bispirooxindoles by 1,3-dipolar cycloaddition of in situ generated azomethine ylides from isatin and proline to different electron-deficient alkenes has been developed. The synthesis affords the desired bispiro scaffold compounds in excellent yields with high regioselectivity under mild conditions. The stereochemistry was determined by single-cry...

Oligonucleotides including C-nucleotides having 1-substitued 1H-1,2,3-triazoles as artificial nucleobases were conveniently synthesized by the post-elongation modification method using the copper(I)-catalyzed alkyne-azide 1,3-dipolar cycloaddition (CuAAC) reaction. The base-pairing properties of the triazole nucleobase analogs in forming duplexes with oligonucleotides were investigated by the T...

The first total synthesis of (+)-5-epi-eudesm-4(15)-ene-1β,6β-diol has been achieved in 12 steps starting from the known (-)-cis-piperitol and by using a chelation controlled glycolate enolate Ireland-Claisen rearrangement and an intramolecular nitrile oxide dipolar cycloaddition as key steps.