C-arylation
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C(8)-H direct arylation of purine derivatives immobilized on Wang resin is described. The purine skeleton was immobilized via C(6)-regioselective substitution of 2,6-dichloropurine with polymer-supported amines. After N(9)-alkylation with two different alkyl iodides and C(2) substitution with two selected amines, reaction conditions for C(8)-H arylation were developed and optimized. Various aryl bromides and aryl iodides were used for the reaction affording the target 2,6,8,9-tetrasubstituted purines in very good purity. The same reaction conditions were also applied for the synthesis of 2,6,8-trisubstituted purines, however, yields were lower. The methodology is applicable for high throughput synthesis of chemical libraries comprised of purine scaffold.
Novel direct C-H borylations of 7-deazapurines to position 8 by B2pin2 under Ir catalysis were followed by Suzuki cross-couplings with aryl halides and other functional group transformations to give diverse 8-substituted 7-deazaadenines.
Structural and electronic features that facilitate and direct the intramolecular C- and N-arylation of 2-alkyl-2-{[N-(benzyl)-2-nitrophenyl]sulfonamido}acetic acid esters and amides were examined. The substitution pattern and amino acid carboxy-terminal functionality determined the arylation position. C/N-arylated products represent advanced intermediates for combinatorial synthesis of diverse nitrogenous heterocycles, including indazoles, quinazolinones, quinoxalinones, and 3-amino-2-oxindoles.
Polymer-supported 2-nitro-N-(2-oxo-2-arylethyl)benzenesulfonamides, prepared from resin-bound amines by sulfonylation with 2-nitrobenzenesulfonyl chlorides followed by alkylation with α-bromoacetophenones, represent advanced intermediates for the synthesis of different nitrogenous heterocycles. We report their application for the synthesis of 2-aryl-3-alkylamino-1H-indoles via base-mediated C-arylation reactions followed by the reduction of the C-arylated intermediates. Linear precursors for C-arylation were prepared on solid-phase support from simple, commercially available building blocks. The effects of different substituents on the amino and aryl groups were addressed.
N-Benzyl-2-nitrobenzenesulfonamides underwent base-mediated intramolecular arylation at the benzyl sp(3) carbon to yield benzhydrylamines. The presence of electron withdrawing groups on the aromatic ring of the benzyl group was required to facilitate the C-arylation. Unsymmetrically substituted benzhydrylamines are advanced intermediates toward nitrogenous heterocycles, as exemplified in the syntheses of indazole oxides and quinazolines.
- MeSH
- alkoholy chemie MeSH
- benzhydrylové sloučeniny chemie MeSH
- benzylové sloučeniny chemie MeSH
- chinazoliny chemická syntéza MeSH
- heterocyklické sloučeniny chemická syntéza MeSH
- indazoly chemická syntéza MeSH
- indikátory a reagencie MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Direct arylation and alkenylation of 1-substituted tetrazoles was achieved via Pd catalysis in the presence of CuI and Cs(2)CO(3). Unlike the related reactions of imidazoles and purines, phosphine ligand was necessary to prevent the intermediate tetrazolyl-Pd(II) species from fragmentation into the corresponding cyanamide. Various 1,5-disubstituted tetrazoles were prepared with good to excellent isolated yields.
Resin-bound intermediates prepared from polymer-supported amino acid esters, 2-nitrobenezenesulfonyl chlorides, and alcohols were used to synthesize 3-alkyl-3-(alkylamino) indolin-2-ones. The key step of the reaction sequence was the formation of a quaternary carbon via the base-mediated C-arylation of 2-nitrobenzenesulfonamides. The cleavage of the acyclic precursors from the resin and subsequent reduction of the nitro group by Zn in acetic acid triggered the spontaneous cyclization of the arylated compounds to indolinones. The synthesis was carried out using simple commercially available building blocks under mild conditions and provided the 3,3-disubstituted indolinone derivatives with good overall yields however, the arylation reaction resulted in the epimerization of the quaternary carbon.
- MeSH
- indoly chemická syntéza chemie MeSH
- molekulární struktura MeSH
- sulfonamidy chemie MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Disruption of microtubules has been shown to cause suppression of inducibility of major cytochromes P450 (CYP) through several nuclear receptors. Here we tested the effects of structurally different clinically used microtubules-interfering agents (MIAs), such as colchicine, vincristine, vinblastine, nocodazole and taxol on aryl hydrocarbon receptor signaling pathway in human hepatocytes. We show that tested MIAs inhibit 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD)-inducible expression of CYP1A2 mRNA and restrict TCDD-dependent nuclear translocation of aryl hydrocarbon receptor. On the other hand, these MIAs increased the content of aryl hydrocarbon receptor protein and mRNA by transcriptional mechanism. We show that the MIAs activate c-Jun -N-terminal kinase (JNK), partly p38 but not extracellular-regulated protein kinase (ERK). Consistently, sorbitol, a model activator of JNK, inhibited TCDD-mediated induction of CYP1A2 mRNA and down-regulated tyrosine aminotransferase mRNA - a target gene of glucocorticoid receptor. Dexamethasone had the opposite effect on aryl hydrocarbon receptor signaling and decreased aryl hydrocarbon receptor mRNA and augmented the inducibility of CYP1A2 by TCDD. We conclude that the effects of tested MIAs on aryl hydrocarbon receptor-CYP1A2 signaling pathway are dual, i.e. they inhibit transcriptional activity and nuclear translocation of aryl hydrocarbon receptor but in parallel increase aryl hydrocarbon receptor protein and mRNA level. Microtubules destabilizers have the same effects as stabilizer taxol. This implies that aryl hydrocarbon receptor functions depend on microtubules dynamics but not integrity. Perturbation of aryl hydrocarbon receptor-CYP1A2 signaling by MIAs comprises glucocorticoid receptor-JNK and probably aryl hydrocarbon receptor-JNK/glucocorticoid receptor interactions. We also demonstrate that the effects of MIAs in human hepatocytes do not proceed via arresting cell cycle as confirmed by flow cytometry (FACS) analyses.
- MeSH
- buněčný cyklus účinky léků MeSH
- cytochrom P-450 CYP1A2 metabolismus účinky léků MeSH
- financování organizované MeSH
- hepatocyty metabolismus účinky léků MeSH
- JNK mitogenem aktivované proteinkinasy metabolismus účinky léků MeSH
- kultivované buňky MeSH
- lidé MeSH
- messenger RNA metabolismus MeSH
- mikrotubuly metabolismus účinky léků MeSH
- modulátory tubulinu farmakologie MeSH
- průtoková cytometrie MeSH
- receptory aromatických uhlovodíků metabolismus účinky léků MeSH
- receptory glukokortikoidů metabolismus účinky léků MeSH
- regulace genové exprese enzymů účinky léků MeSH
- signální transdukce MeSH
- Check Tag
- lidé MeSH
The synthesis and biological activity profiling of a large series of diverse pyrrolo[2,3-d]pyrimidine 4'-C-methylribonucleosides bearing an (het)aryl group at position 4 or 5 is reported as well as the synthesis of several phosphoramidate prodrugs. These compounds are 4'-C-methyl derivatives of previously reported cytostatic hetaryl-7-deazapurine ribonucleosides. The synthesis is based on glycosylation of halogenated 7-deazapurine bases with 1,2-di-O-acetyl-3,5-di-O-benzyl-4-C-methyl-β-d-ribofuranose followed by cross-coupling and nucleophilic substitution reactions. The final compounds showed low cytotoxicity and several derivatives exerted antiviral activity against HCV or Dengue viruses at micromolar concentrations.
- MeSH
- antivirové látky chemická syntéza farmakologie MeSH
- Hepacivirus účinky léků MeSH
- lidé MeSH
- nádorové buněčné linie MeSH
- prekurzory léčiv chemická syntéza farmakologie MeSH
- protinádorové látky chemická syntéza farmakologie MeSH
- purinové nukleosidy chemická syntéza farmakologie MeSH
- purinové nukleotidy chemická syntéza farmakologie MeSH
- virus dengue účinky léků MeSH
- vztahy mezi strukturou a aktivitou MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
A small series of N-aryl-2,6-diphenyl-2H-pyrazolo[4,3-c]pyridin-7-amines was synthesized from easily accessible 1-phenyl-1H-pyrazol-3-ol via 7-iodo-2,6-diphenyl-2H-pyrazolo[4,3-c]pyridine and 7-iodo-4-methyl-2,6-diphenyl-2H-pyrazolo[4,3-c]pyridine intermediates and their subsequent use in palladium catalyzed Buchwald-Hartwig cross-coupling reaction with various anilines. Majority of the compounds were not significantly cytotoxic to melanoma G361 cells in the dark up to 10 μM concentration, but their activity could be increased by irradiation with visible blue light (414 nm). The most active compound 10 possessed EC50 values of 3.5, 1.6 and 0.9 μM in cells irradiated with 1, 5 and 10 J/cm2, respectively. The treatment caused generation of reactive oxygen species in cells and extensive DNA damage, documented by the comet assay and by detection of phosphorylated histone H2A.X, followed by apoptotic cell death. Our results suggest that N-aryl-2,6-diphenyl-2H-pyrazolo[4,3-c]pyridin-7-amines could serve as a potential source of photosensitizing compounds with anticancer activities.
- MeSH
- fotochemoterapie * MeSH
- fotosenzibilizující látky chemická syntéza chemie farmakologie MeSH
- lidé MeSH
- melanom farmakoterapie metabolismus patologie MeSH
- molekulární struktura MeSH
- nádorové buňky kultivované MeSH
- nádory kůže farmakoterapie metabolismus patologie MeSH
- proliferace buněk účinky léků MeSH
- protinádorové látky chemická syntéza chemie farmakologie MeSH
- screeningové testy protinádorových léčiv MeSH
- světlo MeSH
- viabilita buněk účinky léků MeSH
- vztah mezi dávkou a účinkem léčiva MeSH
- vztahy mezi strukturou a aktivitou MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
