Bromination at C-5 of pyrimidine and C-8 of purine nucleosides with 1,3-dibromo-5,5-dimethylhydantoin

Rayala, Ramanjaneyulu; Wnuk, Stanislaw F.

doi:10.1016/j.tetlet.2012.04.081

Cited by 24 publications

(25 citation statements)

References 30 publications

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“…Thus, bromination of 2',3',5'-tri- O -acetyltubercidin 1a using recently reported protocols for the C-8 bromination of purine nucleosides, 34 employing 1,3-dibromo-5,5-dimethylhydantoin (DBH, 0.65 eq.) in CH 2 Cl 2 at 0 °C for 40 min, provided 7-bromo 2a (32%) in addition to 7,8-dibromo 2b (10%, TLC; Scheme 1).…”

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confidence: 99%

Synthesis of 8-(1,2,3-triazol-1-yl)-7-deazapurine nucleosides by azide–alkyne click reactions and direct C H bond functionalization

Kavoosi

Rayala

Walsh

et al. 2016

Tetrahedron Letters

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Treatment of toyocamycin or sangivamycin with 1,3-dibromo-5,5-dimethylhydantoin in MeOH (r.t./30 min) gave 8-bromotoyocamycin and 8-bromosangivamycin in good yields. Nucleophilic aromatic substitution of 8-bromotoyocamycin with sodium azide provided novel 8-azidotoyocamycin. Strain promoted click reactions of the latter with cyclooctynes resulted in the formation of the 1,2,3-triazole products. Iodine-mediated direct C8-H bond functionalization of tubercidin with benzotriazoles in the presence of tert-butyl hydroperoxide gave the corresponding 8-benzotriazolyltubercidin derivatives. The 8-(1,2,3-triazol-1-yl)-7-deazapurine derivatives showed moderate quantum yields and a large Stokes shifts of ~ 100 nm.

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confidence: 99%

Synthesis of 8-(1,2,3-triazol-1-yl)-7-deazapurine nucleosides by azide–alkyne click reactions and direct C H bond functionalization

Kavoosi

Rayala

Walsh

et al. 2016

Tetrahedron Letters

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“…)/CH 2 Cl 2 /35 °C/15 h gave complex reaction mixture. 48 Also, attempted fluorination of readily available 50 2'- S -aryl-2'-thiouridine analogues of type 6 51 (Scheme 2) or 2'- S -aryl-2'-fluoro-2'-thiouridine analogues of type 8 51 (Scheme 3) with Py.9HF/DBH failed to give 2',2'-difluoro products yielding instead 5-brominated 52 products as well as the corresponding sulfoxides and/or α-fluoro sulfoxides, among other byproducts. Installing different protection groups on sugar hydroxyls (Ac, Bn) and EDG (MeO) or EWG (Cl) in phenyl ring as well as changing reaction conditions (e.g., halogen source, temperature, reaction time) did not change the outcome.…”

Section: Resultsmentioning

confidence: 99%

“…Moreover, treatment of α-fluorothioether 8 with DBH/Py.9HF at −78 °C effected selective bromination of the uracil ring at the C5 position 52 yielding the corresponding 5-bromo derivative 9 as a major product (50%), however with no indication of the geminal difluoro product formation (Scheme 3). Interestingly, the α-fluoro thioether moiety in 9 remained intact under these oxidative conditions.…”

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confidence: 99%

Studies toward the oxidative and reductive activation of C–S bonds in 2′-S-aryl-2ʹ-thiouridine derivatives

et al. 2016

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Studies directed toward the oxidative and reductive desulfurization of readily available 2'-S-aryl-2'-thiouridine derivatives were investigated with the prospect to functionalize the C2'-position of nucleosides. The oxidative desulfurization-difluorination strategy was successful on 2-(arylthio)alkanoate surrogates, while extension of the combination of oxidants and fluoride sources was not an efficient fluorination protocol when applied to 2'-S-aryl-2'-thiouridine derivatives, resulting mainly in C5-halogenation of the pyrimidine ring and C2'-monofluorination without desulfurization. Cyclic voltammetry of 2'-arylsulfonyl-2'-deoxyuridines and their 2'-fluorinated analogues showed that cleavage of the arylsulfone moiety could occur, although at relatively high cathodic potentials. While reductive-desulfonylation of 2'-arylsulfonyl-2'-deoxyuridines with organic electron donors (OEDs) gave predominantly base-induced furan type products, chemical (OED) and electrochemical reductive-desulfonylation of the α-fluorosulfone derivatives yielded the 2'-deoxy-2'-fluorouridine and 2',3'-didehydro-2',3'-dideoxy-2'-fluorouridine derivatives. These results provided good evidence of the generation of a C2'-anion through carbon-sulfur bond cleavage, opening new horizons for the reductive-functionalization approaches in nucleosides.

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“…The latter coupling must be run in the dark in order to avoid the known photolysis of 22 caused by UV irradiation. 48 Substrate 22 was prepared by conversion of 5-bromo-2′-deoxyuridine 71 to 5-amino derivative followed by Sandmeyer azidation. 70 …”

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confidence: 99%

Strain Promoted Click Chemistry of 2- or 8-Azidopurine and 5-Azidopyrimidine Nucleosides and 8-Azidoadenosine Triphosphate with Cyclooctynes. Application to Living Cell Fluorescent Imaging

Zayas¹,

Annoual²,

Das³

et al. 2015

Bioconjugate Chem.

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Strain-promoted click chemistry of nucleosides and nucleotides with an azido group directly attached to the purine and pyrimidine rings with various cyclooctynes in aqueous solution at ambient temperature resulted in efficient formation (3 min - 3 h) of fluorescent, light-up, triazole products. The 2- and 8-azidoadenine nucleosides reacted with fused cyclopropyl cyclooctyne, dibenzylcyclooctyne or monofluorocyclooctyne to produce click products functionalized with hydroxyl, amino, N-hydroxysuccinimide, or biotin moieties. The 5-azidouridine and 5-azido-2′-deoxyuridine were similarly converted to the analogous triazole products in quantitative yields in less than 5 minutes. The 8-azido-ATP quantitatively afforded the triazole product with fused cyclopropyl cyclooctyne in aqueous acetonitrile (3 h). The novel triazole adducts at the 2 or 8 position of adenine or 5-position of uracil rings induce fluorescence properties which were used for direct imaging in MCF-7 cancer cells without the need for traditional fluorogenic reporters. FLIM of the triazole click adducts demonstrated their potential utility for dynamic measuring and tracking of signaling events inside single living cancer cells.

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Bromination at C-5 of pyrimidine and C-8 of purine nucleosides with 1,3-dibromo-5,5-dimethylhydantoin

Cited by 24 publications

References 30 publications

Synthesis of 8-(1,2,3-triazol-1-yl)-7-deazapurine nucleosides by azide–alkyne click reactions and direct C H bond functionalization

Synthesis of 8-(1,2,3-triazol-1-yl)-7-deazapurine nucleosides by azide–alkyne click reactions and direct C H bond functionalization

Studies toward the oxidative and reductive activation of C–S bonds in 2′-S-aryl-2ʹ-thiouridine derivatives

Strain Promoted Click Chemistry of 2- or 8-Azidopurine and 5-Azidopyrimidine Nucleosides and 8-Azidoadenosine Triphosphate with Cyclooctynes. Application to Living Cell Fluorescent Imaging

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