- Room-Temperature Amination of Chloroheteroarenes in Water by a Recyclable Copper(II)-Phosphaadamantanium Sulfonate System
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Buchwald-Hartwig amination of chloroheteroarenes has been a challenging synthetic process, with very few protocols promoting this important transformation at ambient temperature. The current report discusses about an efficient copper-based catalytic system (Cu/PTABS) for the amination of chloroheteroarenes at ambient temperature in water as the sole reaction solvent, a combination that is first to be reported. A wide variety of chloroheteroarenes could be coupled efficiently with primary and secondary amines as well as selected amino acid esters under mild reaction conditions. Catalytic efficiency of the developed protocol also promotes late-stage functionalization of active pharmaceutical ingredients (APIs) such as antibiotics (floxacins) and anticancer drugs. The catalytic system also performs efficiently at a very low concentration of 0.0001 mol % (TON = 980,000) and can be recycled 12 times without any appreciable loss in activity. Theoretical calculations reveal that the π-acceptor ability of the ligand PTABS is the main reason for the appreciably high reactivity of the catalytic system. Preliminary characterization of the catalytic species in the reaction was carried out using UV-VIS and ESR spectroscopy, providing evidence for the Cu(II) oxidation state.
- Dandela, Rambabu,Desai, Aman A.,Kapdi, Anant R.,Kori, Santosh,Maity, Dilip K.,Parmar, Udaysinh,Somvanshi, Dipesh
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p. 8900 - 8925
(2021/07/20)
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- Medicinal Chemistry Optimization of a Diaminopurine Chemotype: Toward a Lead for Trypanosoma brucei Inhibitors
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Human African trypanosomiasis (HAT), or sleeping sickness, is caused by the protozoan parasite Trypanosoma brucei and transmitted through the bite of infected tsetse flies. The disease is considered fatal if left untreated. To identify new chemotypes against Trypanosoma brucei, previously we identified 797 potent kinase-targeting inhibitors grouped into 59 clusters plus 53 singleton compounds with at least 100-fold selectivity over HepG2 cells. From this set of hits, a cluster of diaminopurine-derived compounds was identified. Herein, we report our medicinal chemistry investigation involving the exploration of structure-activity and structure-property relationships around one of the high-throughput screening (HTS) hits, N2-(thiophen-3-yl)-N6-(2,2,2-trifluoroethyl)-9H-purine-2,6-diamine (1, NEU-1106). This work led to the identification of a potent lead compound (4aa, NEU-4854) with improved in vitro absorption, distribution, metabolism, and excretion (ADME) properties, which was progressed into proof-of-concept translation of in vitro antiparasitic activity to in vivo efficacy.
- Singh, Baljinder,Diaz-Gonzalez, Rosario,Ceballos-Perez, Gloria,Rojas-Barros, Domingo I.,Gunaganti, Naresh,Gillingwater, Kirsten,Martinez-Martinez, Maria Santos,Manzano, Pilar,Navarro, Miguel,Pollastri, Michael P.
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p. 9912 - 9927
(2020/10/19)
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- HFIP Promoted Low-Temperature SNAr of Chloroheteroarenes Using Thiols and Amines
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A highly efficient and an unprecedented hexafluoro-2-propanol, promoting low-temperature aromatic nucleophilic substitutions of chloroheteroarenes, has been performed using thiols and (secondary) amines under base-free and metal-free conditions. The developed protocol also provides excellent regio-control for the selective functionalization of dichloroheteroarenes, while the utility of the protocol was demonstrated by the modification of a commercially available drug ceritinib.
- Bhujabal, Yuvraj B.,Vadagaonkar, Kamlesh S.,Gholap, Aniket,Sanghvi, Yogesh S.,Dandela, Rambabu,Kapdi, Anant R.
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p. 15343 - 15354
(2019/12/04)
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- Design, synthesis and evaluation of 4-aminoquinoline-purine hybrids as potential antiplasmodial agents
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A novel series of 4-aminoquinoline-purine hybrids were synthesized and assessed for their antiplasmodial activity against CQ-sensitive and CQ-resistant strains of P. falciparum. It was envisaged that linking of the 4-aminoquinoline pharmacophore (targeting heme-detoxification pathway of malarial parasite) with the purine functionality (targeting plasmodial HG(X)PRT enzyme) will produce a hybrid antiplasmodial agent with increased potency. The synthesized hybrids displayed good antiplasmodial activities against both the sensitive and resistant strains of P. falciparum with up to six-fold better activity (compound 10i, IC50: 0.08?μM) compared to the reference drug CQ (IC50: 0.5?μM) against the resistant strain. The synthesized compounds were also checked for their cytotoxicity towards mammalian cells and with the exception of two compounds out of the twenty synthesized hybrids, all others were non-cytotoxic up to 11.86?μM concentration. Mechanistic heme-binding studies were performed to identify the mechanism of action of the synthesized molecules and good binding interactions were observed. Computational docking studies showed that the most active hybrids dock well within the binding site of HGPRT protein. In silico ADME predictions of the most active hybrids showed that these compounds possess good pharmacokinetic behavior.
- Reddy, P. Linga,Khan, Shabana I.,Ponnan, Prija,Tripathi, Mohit,Rawat, Diwan S.
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p. 675 - 686
(2016/12/14)
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- Synthesis of Chiral Cyclopropyl Carbocyclic Purine Nucleosides via Asymmetric Intramolecular Cyclopropanations Catalyzed by a Chiral Ruthenium(II) Complex
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The synthesis of chiral cyclopropyl carbocyclic purine nucleoside analogues via the highly enantioselective intramolecular cyclopropanation reactions has been reported. With a chiral ruthenium(II)-phenyloxazoline complex as the catalyst, cyclopropyl carbocyclic purine nucleoside analogues containing three contiguous stereocenters were obtained with up to 99% yield and 99% ee. Furthermore, a chiral cyclopropyl carbocyclic adenosine nucleoside having anti-BLV activity could be synthesized in a concise manner using this strategy. (Figure presented.).
- Huang, Ke-Xin,Xie, Ming-Sheng,Zhao, Guo-Feng,Qu, Gui-Rong,Guo, Hai-Ming
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supporting information
p. 3627 - 3632
(2016/11/25)
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- Novel purine and pyrazolo[3,4-d]pyrimidine inhibitors of PI3 kinase-α: Hit to lead studies
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Series of purine and pyrazolo[3,4-d]pyrimidine inhibitors of phosphatidylinositol-3-kinases (PI3K) have been prepared. The optimized purine inhibitors show good potency in a PI3K p110α (PI3K-α) fluorescence polarization assay with good selectivity versus PI3K p110γ (PI3K-γ) and the mammalian target of rapamycin (mTOR). The related pyrazolo[3,4-d]pyrimidines show potent PI3K-α and mTOR inhibition with good selectivity versus PI3K-γ. Representative compounds showed activity in a cellular proliferation assay against Caco-2 colorectal, LoVo colorectal and PC3MM2 prostate adenocarcinoma cancer cells. Signaling through the PI3K pathway was confirmed via inhibition of phospho-AKT in MDA-361 cells.
- Gilbert, Adam M.,Nowak, Pawel,Brooijmans, Natasja,Bursavich, Matthew G.,Dehnhardt, Christoph,Santos, Efren Delos,Feldberg, Larry R.,Hollander, Irwin,Kim, Stephen,Lombardi, Sabrina,Park, Kaapjoo,Venkatesan, Aranapakam M.,Mallon, Robert
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scheme or table
p. 636 - 639
(2010/06/14)
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- Purine Derivatives, Compositions Containing Them and Use Thereof
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Purine derivatives of formula (IA1) or (IB1), compositions containing them and use thereof as medicinal products, in particular in oncology, are described
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Page/Page column 9
(2008/12/05)
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