- Synthesis, DNA-binding and photocleavage of "light switch" complexes [Ru(bpy)2(pyip)]2+ and [Ru(phen) 2(pyip)]2+
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Two novel Ru(II) complexes [Ru(bpy)2(pyip)]2+ 1 and [Ru(phen)2(pyip)]2+ 2 (bpy = 2,2′-bipyridine; phen = 1,10-phenanthroline; pyip = 2-(pyridine-2-yl)imidazo-[4,5-f][1,10]- phenanthroline), have been synthesized and characterized by elemental analysis, ES-MS, 1H NMR, UV-Vis. The DNA-binding behaviors of both complexes were studied by spectroscopic methods and viscosity measurements. The results indicate that the two complexes can bind to CT-DNA in an intercalative mode, and also show that these two Ru(II) complexes can promote the photocleavage of pBR322 DNA. In addition, In the presence of Co2+, the emission of DNA-[Ru(L)2pyip]2+ can be quenched, which exhibited the DNA "light switch" properties.
- Liu, Xue-Wen,Shen, You-Ming,Lu, Ji-Lin,Chen, Yuan-Dao,Li, Lin,Zhang, Da-Shun
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- Tetranuclear Lanthanide Complexes Containing a Hydrazone-type Ligand. Dysprosium [2 × 2] Gridlike Single-Molecule Magnet and Toroic
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A multidentate hydrazone-type ligand (Z,Z)-bis(1-(pyridin-2-yl)-1-amino-methylidene)oxalohydrazide (H2L) was utilized in the synthesis of three new isomorphous tetranuclear complexes of the general formula [Ln4(HL)4(H2L)2(NO3)4](NO3)4·4CH3OH (Ln = GdIII, 1, TbIII, 2, DyIII, 3) with the gridlike [2 × 2] topology. The analysis of the static magnetic data revealed weak anti-ferromagnetic interaction among lanthanide(III) atoms, whereas dynamic magnetic data led to the observation of the single-molecule magnet behavior in zero static magnetic field for the Dy4 compound 3 with Ueff = 42.6 K and τ0 = 1.50 × 10-5 s. The theoretical CASSCF calculations supported also the presence of the net toroidal magnetic moment, which classifies compound 3 also as a single-molecule toroic.
- Gusev, Alexey,Herchel, Radovan,Nemec, Ivan,Shul'gin, Victor,Eremenko, Igor L.,Lyssenko, Kostantin,Linert, Wolfgang,Trávní?ek, Zdeněk
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- In vitro and in vivo biological effects of novel arylimidamide derivatives against Trypanosoma cruzi
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Chagas disease (CD), a neglected tropical disease caused by Trypanosoma cruzi, remains a serious public health problem in several Latin American countries. The available chemotherapies for CD have limited efficacy and exhibit undesirable side effects. Aro
- Timm, Bruno Lisboa,Da Silva, Patricía Bernadino,Batista, Marcos Meuser,Da Silva, Francisca Hildemagna Guedes,Da Silva, Cristiane Fran?a,Tidwell, Richard R.,Patrick, Donald A.,Jones, Susan Kilgore,Bakunov, Stanislav A.,Bakunova, Svetlana M.,Soeiro, Maria De Nazaré C.
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- Self assembled tetranuclear Cu4(ii), Ni4(ii) [2 × 2] square grids and a dicopper(ii) complex of heterocycle based polytopic ligands - Magnetic studies
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The ditopic ligand PyPzOAP (N-[(Z)-amino(pyridin-2-yl)methylidene]-5- methyl-1-(pyridin-2-yl)-1H-pyrazole-3-carbohydrazonic acid) and the polytopic ligand 2-PzCAP (N′3,N′5-bis[(1E)-1-(pyridin-2- yl)ethylidene]-1H-pyrazole-3,5-dicarbo
- Mandal, Tarak Nath,Roy, Somnath,Konar, Saugata,Jana, Atanu,Ray, Sangita,Das, Kinsuk,Saha, Rajat,El Fallah, Mohamed Salah,Butcher, Ray J.,Chatterjee, Sudipta,Kar, Susanta Kumar
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- Cyanoamidines. I. Synthesis and vasodilatory activity of N-substituted heteroaromatic cyanoamidines
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Various heteroaromatic cyanoamidines were synthesized starting from nitriles via cyanoimidates or from amides via thioamides. The compounds were tested for inhibitory effect on the 40 mM K+-induced contraction of rat aorta strips and selected compounds were also evaluated for antagonism of the norepinephrine-induced contraction. Most of the cyanoamidines showed vasodilatory activities. Potent vasoactive compounds were also examined for stimulation of the 86Rb+ efflux to determine their potassium channel opening actions. Maximum potency was displayed by N-cyano-N'-(2-nitroxyethyl)-3-pyridinecarboxamidine (3h). The methanesulfonate of 3h, which was designated as KRN2391, has been selected for further development as an antianginal agent.
- Nakajima,Izawa,Kashiwabara,Nakajima,Munezuka
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- The First Dinuclear μ-Hexafluorosilicato Copper(II) Compound. Synthesis and Crystal Structure of (μ-Hexafluorosilicato-κF:κF')-bis3-salicyloylpyridine-2-carboxamidrazonato-κ3N',N2,O)copper(II)> Dihydrate
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The X-ray structure of a unique dinuclear copper(II) compound containing a single hexafluorosilicato bridge, *2H2O (HL = N3-salicyloylpyridine-2-carboxamidrazone), is reported.
- Koningsbruggen, Petra J. van,Haasnoot, Jaap G.,Graaff, Rudolf A. G. de,Reedijk, Jan
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- Synthesis of 2-pyridyl oxazoline esters and their organocatalytic application to the enantioselective silane reduction of ketones
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The synthesis of a number of novel chiral 2-pyridyl oxazoline esters is reported along with the use of these in the enantioselective organocatalytic reduction of ketones. The chiral alcohols were prepared in good to excellent yields (up to 99%) and were f
- Cao, Zhenyu,McCleary, Nadine,O’Leary, Patrick
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- New iridium complex as high-efficiency red phosphorescent emitter in polymer light-emitting devices
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A new heteroleptic iridium complex Ir(1-piq)2pt with 1-phenylisoquinoline and 3-(pyridin-2′-yl)-1H-1,2,4-triazole was synthesized and characterized. The complex was incorporated into phosphorescent polymer light-emitting devices using polyhedral oligomeric silsesquioxane- terminated polyfluorene (PFO-poss) as a host polymer doped with 30% of electron transport materials 2-(4-biphenylyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole (PBD). Red electrophosphorescence was observed with a peak emission at 605 nm. The highest-efficiency polymer light-emitting diode was achieved with PFO-poss doped with 2% Ir(1-piq)2pt. An external quantum efficiency of 10.4% and a luminous efficiency of 9.4 cd A-1 were obtained at 10.8 mA cm-2. These values were found to be 7.67% and 5.99 cd A-1 at 100 mA cm-2.
- Liang, Bo,Jiang, Changyun,Chen, Zhao,Zhang, Xiuju,Shi, Huahong,Cao, Yong
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- Supramolecular metal helicate structures with incomplete metal ion coordination
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Two flexible 'polytopic' ligands take part in self assembly reactions with Ni(II) salts to produce helical structures, with 'incomplete' metal ion coordination, and the occupancy of empty coordination pockets by a water molecule and a putative fluoride ion. [Ni3(pd2am-H)3(H2O)](NO3) 3·2H2O 1 consists of a localized Ni2(N-N)3 dinuclear centre with three N-N single bond bridges, and a distant mono-nuclear Ni(II) centre, within the same molecular ion, and [Ni2(2pzoap)3F](BF4)3 ·8.5H2O 2 has a dinuclear stucture with two well separated octahedral Ni(II) sites. In both cases a single entity (H2O 1, F- 2) occupies a potential coordination pocket. Antiferromagnetic coupling is observed between the adjacent Ni(II) centres in 1, associated with the N-N bridging interactions, but the distant metal centres in 2 are uncoupled.
- Thompson,Matthews,Zhao,Wilson,Leech,Howard
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- Self-assembled polymetallic square grids ([2 × 2] M4, [3 × 3] M9) and trigonal bipyramidal clusters (M5) - Structural and magnetic properties
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New self-assembled grids and clusters are reported, with square [2 × 2] M4 (M = Mn(ii)4, Cu(ii)4), trigonal-bipyramidal Mn(ii)5, and square [3 × 3] M9 (M = Mn(ii), Cu(ii)) examples. These are based on a series of ditopic and tritopic hydrazone ligands involving pyridine, pyrimidine and imidazole end groups. In all cases the metal centres are bridged by hydrazone oxygen atoms with large (>125°) bridge angles, leading to antiferromagnetic exchange for all the Mn systems (J = -2 to -5 cm-1), which results in S = 0 (Mn4), and S = 5/2 (Mn5, Mn9) ground states. The copper systems have a 90° alternation of the Jahn-Teller axes within the Cu4 and Cu8 grid rings (Cu9), which leads to magnetic orbital orthogonality, and dominant ferromagnetic coupling. For the Cu9 grid antiferromagnetic exchange between the ring and the central copper leads to a S = 7/2 ground state, while for the Cu4 grids S = 4/2 ground states are observed. The magnetic data have been treated using isotropic exchange models in the cases of the Cu4 and Cu9 grids, and the Mn5 clusters. However due to the enormity of a fully isotropic calculation a simplified model is used for the Mn9 grid, in which the outer Mn8 ring is treated as the equivalent of an isolated magnetic chain, with no coupling to the central metal ion. The Royal Society of Chemistry 2006.
- Dawe, Louise N.,Abedin, Tareque S. M.,Kelly, Timothy L.,Thompson, Laurence K.,Miller, David O.,Zhao, Liang,Wilson, Claire,Leech, Michael A.,Howard, Judith A. K.
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- Self-assembled polynuclear clusters derived from some flexible polydentate dihydrazide ligands
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Polynuclear manganese(II), cobalt(II)/(III), iron(II)/(III) and nickel(II) complexes of a group of flexible polydentate dihydrazone ligands, based on pyridine-2,6-dipicolinic (A), oxalic (B) and malonic (C) subunits are described. Structural details are reported for the linear dinuclear complexes [Ni 2(2poap)2(H2O)2](NO 3)4·2CH3OH·2.5H2O (1), [Mn2(pttp)(NO3)2(CH3OH) 2(H2O)2](NO3) 2·H2O (2) and [Mn2(mapttp) 2(NO3)2(H2O)2](NO 3)2·10H2O (3), a square tetranuclear complex [Co4(pttp)4]Br6·9H2O (4), a tetranuclear tetrahedral complex [Ni4(pttp) 6](BF4)6F2·14H2O (7), and a mixed spin state tetranuclear Ni(II) complex [(2pyoap) 2Ni4(CH3OH)4]·1.5CH 3OH (10), with a diamond-like arrangement of metal ions. The paramagnetic metal centers are well separated in each case, leading to weak antiferromagnetic coupling or non-existent spin exchange.
- Zhao, Liang,Niel, Virginie,Thompson, Laurence K.,Xu, Zhiqiang,Milway, Victoria A.,Harvey, Rosemary G.,Miller, David O.,Wilson, Claire,Leech, Michael,Howard, Judith A.K.,Heath, Sarah L.
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- Syntheses, characterization, and X-ray crystal structures of two cis-dioxovanadium(V) complexes of pyrazole-derived, Schiff-base ligands
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Two mononuclear cis-dioxovanadium(V) complexes of pyrazole-derived, Schiff-base ligands have been synthesized and characterized. Single crystal X-ray analyses were performed with N '-[(3-methyl-1H-pyrazole-5-yl)carbonyl] pyridine-2-carbohadrazonamido cis-dioxovanadium(V), {[VO2(PzOAP)] H2O} (1), and 5-methyl-N-[(1E)-1-(pyridin-2-yl)ethylidene]-1H- pyrazole-3-carbohydrazonate cis-dioxovanadium(V), {[VO2(PzCAP)]} (2). Both complexes crystallize in monoclinic crystal systems with different space groups. Complex 1 crystallizes in the space group P21/c, 2 in space group C2/C. In each complex, the vanadium sits within a distorted square pyramidal geometry with an N2O3 chromophore. The parameters of the complexes (0.33 for 1, 0.22 for 2) support their square pyramidal geometry. The interesting finding in the work is that the alkoxide oxygen, imino nitrogen, and pyridine nitrogen take part in the coordination process leaving the pyrazole rings inactive in coordination.
- Roy, Somnath,Mandal, Tarak Nath,Das, Kinsuk,Butcher, Ray J.,Rheingold, Arnold L.,Kumar Kar, Susanta
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- Syntheses, characterization, X-ray crystal structures and emission properties of five oxovanadium(V) complexes with pyridyl/pyrimidyl-pyrazole derived ditopic ligands
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Four oxovanadium(V) complexes of heterocycle based ditopic ligands PyPzOAP (N-[amino(pyridin-2-yl)methylidene]-5-methyl-1-(pyridin-2-yl) -1H-pyrazole-3-carbohydrazonic acid), PyPzOAPz (N-[amino(pyrazin-2-yl) methylidene]-5-methyl-1-(pyridin-2-yl)-1H-pyrazole-3-carbohydrazonic acid), PymPzOAP (N-[amino(pyridin-2-yl)methylidene]-1-(4,6-dimethylpyrimidin-2-yl)-5- methyl-1H-pyrazole-3-carbohydrazonic acid) and PyPzCAP (5-methyl-1-(pyridin-2- yl)-N′-[1-(pyridin-2-yl)ethylidene]-1H-pyrazole-3-carbohydrazide) and a binuclear (di-μ-oxo) oxovanadium(V) complex of the ligand PymPzCAP (1-(4,6-dimethylpyrimidin-2-yl)-5-methyl-N′-[1-(pyridin-2-yl)ethylidene] -1H-pyrazole-3-carbohydrazide) have been investigated. The ligands act as uninegative NNO tridentates donors for the VO2+ ion exhibiting their monotopicity. The ligands show varying emission properties due to the presence of fluophoric groups like 1-(2-pyridyl)pyrazole or 1-(2-pyrimidyl)pyrazole. The vanadium(V) complexes show fluorescence quenching with respect to the used ligands to a varying extent. The complexes were characterized by UV-Vis, IR, cyclic voltammetry and X-ray crystallography.
- Mandal, Tarak Nath,Roy, Somnath,Gupta, Samik,Paul, Bijan Kumar,Butcher, Ray J.,Rheingold, Arnold L.,Kar, Susanta Kumar
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- An orthogonal ferromagnetically coupled tetracopper(II) 2 × 2 homoleptic grid supported by -O4 bridges and its DFT study
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A pyrazole based ditopic ligand (PzOAP), prepared by the reaction between 5-methylpyrazole-3-carbohydrazide and methyl ester of imino picolinic acid, reacts with Cu(NO3)2·6H2O to form a self-assembled, ferromagnetically coupled, alkoxide bridged tetranuclear homoleptic Cu(ii) square grid-complex [Cu4(PzOAP)4(NO 3)2] (NO3)2·4H2O (1) with a central Cu4[-O4] core, involving four ligand molecules. In the Cu4[-O4] core, out of four copper centers, two copper centers are penta-coordinated and the remaining two are hexa-coordinated. In each case of hexa-coordination, the sixth position is occupied by the nitrate ion. The complex 1 has been characterized structurally and magnetically. Although Cu-O-Cu bridge angles are too large (138-141°) and Cu-Cu distances are short (4.043-4.131 A), suitable for propagation of expected antiferromagnetic exchange interactions within the grid, yet intramolecular ferromagnetic exchange (J = 5.38 cm-1) is present with S = 4/2 magnetic ground state. This ferromagnetic interaction is quite obvious from the bridging connections (dx2-y2) lying almost orthogonally between the metal centers. The exchange pathways parameters have been evaluated from density functional calculations. The Royal Society of Chemistry 2007.
- Roy, Somnath,Mandal, Tarak Nath,Barik, Anil Kumar,Pal, Sachindranath,Butcher, Ray J.,El Fallah, Mohamed Salah,Tercero, Javier,Kar, Susanta Kumar
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- Synthesis of 1-naphtylpiperazine derivatives as serotoninergic ligands and their evaluation as antiproliferative agents
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Serotonin (5-hydroxytryptamine, 5-HT) is one of the most important neuromediator involved in numerous physiological and pathophysiological processes. In addition it is well established that 5-HT acts as a growth factor on several types of non-tumoral and tumoral cells, and recently it was also related to oncogenes. 5-HT1A receptor expression was identified in prostatic tumor cell lines (PC3 cells) and in human hormone refractory prostate cancer tissue. Based on these observations, development of 5-HT1A antagonists could be useful in inhibiting the growth of cancer cells. In order to investigate on potential use of 5-HT1A ligands as antiproliferative agents, we have analyzed a new set of 1-naphtylpiperazine derivatives. In binding studies, several molecules showed affinity in nanomolar and subnanomolar range at 5-HT1A and moderate to no affinity for other relevant receptors (5-HT2A, 5-HT2C, D1, D2, α1 and α2). All compounds were then evaluated in order to assess their antiproliferative activity using PC3 cells and the most active compounds (1 and 2) were fully characterized to define the mechanism responsible for the observed antiproliferative effect.
- Fiorino, Ferdinando,Magli, Elisa,Perissutti, Elisa,Severino, Beatrice,Frecentese, Francesco,Esposito, Antonella,De Angelis, Francesca,Incisivo, Giuseppina Maria,Massarelli, Paola,Nencini, Cristina,Di Gennaro, Elena,Budillon, Alfredo,Di Cintio, Alessandra,Santagada, Vincenzo,Caliendo, Giuseppe
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- In vitro and in vivo trypanosomicidal action of novel arylimidamides against trypanosoma cruzi
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Arylimidamides (AIAs) have been shown to have considerable biological activity against intracellular pathogens, including Trypanosoma cruzi, which causes Chagas disease. In the present study, the activities of 12 novel bis-AIAs and 2 mono-AIAs against dif
- Guedes-Da-Silva,Batista,Meuser,Demarque,Fulco,Araújo,Da Silva,Da Silva,Patrick,Bakunova,Bakunov,Tidwell,Oliveira,Britto,Moreira,Soeiro
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- Complete and 'incomplete' [2 × 2] grids by self-assembly with a sterically hindered ditopic imidazole hydrazone ligand-structural and magnetic studies
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A ditopic hydrazone ligand (ioap) synthesized from the condensation of 4-methyl-5-imidazole carboxylic acid hydrazide with the iminoester of 2-pyridinecarbonitrile formed targeted [2 × 2] M4L4 (M = Cu(ii), Ni(ii); L = ioap) grids, and a mixed oxidation state dinuclear cobalt complex. An 'incomplete' trinuclear M3L4 (M = Mn(ii)) grid, based on a [2 × 2] grid architecture, resulting from steric congestion of the imidazole methyl-substituent, was also produced. These results lead to the suggestion of one possible route to the self-assembly pathway of the [2 × 2] grids. The Mn(ii), Ni(ii) and Cu(ii) complexes have hydrazone oxygen bridges between metal centres, which lead to antiferromagnetic exchange in the Mn(ii)3 and Ni(ii)4 cases, but, due to the presence of orthogonal bridging connections, to ferromagnetic exchange for the Cu(ii)4 example. Structural and magnetic properties are discussed based on the bridging connections.
- Dawe, Louise N.,Thompson, Laurence K.
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- New palladium(ii) complexes with 3-(2-pyridyl)-5-alkyl-1,2,4-triazole ligands as recyclable C-C coupling catalysts
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A series of palladium(ii) complexes with 3-(2-pyridyl)-5R-1,2,4-triazoles Pd(LR)2 (R = ethyl (4a), n-propyl (4b), i-propyl (4c) and t-butyl (4d)) have been synthesised and characterised by NMR, IR, UV-vis spectroscopy, ESI and MALDI-
- Zakharchenko, Borys V.,Khomenko, Dmytro M.,Doroshchuk, Roman O.,Raspertova, Ilona V.,Starova, Viktoriia S.,Trachevsky, Volodymyr V.,Shova, Sergiu,Severynovska, Olga V.,Martins, Luísa M. D. R. S.,Pombeiro, Armando J. L.,Arion, Vladimir B.,Lampeka, Rostyslav D.
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- High steric hindrance chiral P, N, N ligand compound, preparation method and applications thereof
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The invention provides a high steric hindrance chiral P, N, N ligand compound, a preparation method and applications thereof, wherein the ligand has a structural formula represented by (S)-L and (R)-L. The preparation method comprises: (1) preparing an or
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Paragraph 0105; 0106
(2019/07/04)
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- Synthesis, docking studies, and pharmacological evaluation of 5HT2C ligands containing the N′-cyanoisonicotinamidine or N′-cyanopicolinamidine nucleus
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N′-Cyanoisonicotinamidine and N′-cyanopicolinamidine derivatives, linked to an arylpiperazine moiety, were prepared and their affinities to the 5-HT1A, 5-HT2A, and 5-HT2C receptors were evaluated. Several of the newly synthesized compounds, tested by binding studies, showed nanomolar affinity at the 5-HT1A and 5-HT2C receptors and moderate or no affinity for other relevant receptors (D1, D2, α1, and α2). Compound 8e (Ki = 21.4 nM) was the most affine for the 5-HT2C receptor, showing, at the same time, a high selectivity with respect to the other receptors analyzed. Compounds 4a and 4c, instead, showed an interesting mixed 5-HT1A/5-HT2C activity with Ki values of 21.3/11.5 and 23.2/6.48 nM, respectively. The compounds with better affinity and selectivity binding profiles toward 5-HT2C (4a, 4c, 8b, and 8e) were selected for further in vivo assays to determine their functional activity. Finally, to rationalize the obtained results, molecular docking studies were performed. The results of the pharmacological studies showed that compounds 4a, 8b, and 8e exerted antidepressant-like effects and 4a and 8e revealed also significant anxiolytic properties. Among the developed derivatives, the most promising compound seems to be 4a, which displayed antipsychotic-, antidepressant- and anxiolytic-like properties. No side effects, like catalepsy, motor-impairment or ethanol-potentiating effects, were observed after the injection of the tested compounds.
- Magli, Elisa,K?dzierska, Ewa,Kaczor, Agnieszka A.,Severino, Beatrice,Corvino, Angela,Perissutti, Elisa,Frecentese, Francesco,Saccone, Irene,Massarelli, Paola,Gibu?a-Tar?owska, Ewa,Kotlińska, Jolanta H.,Santagada, Vincenzo,Caliendo, Giuseppe,Fiorino, Ferdinando
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- Enantioselective Synthesis of N-Benzylic Heterocycles: A Nickel and Photoredox Dual Catalysis Approach
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Reported herein is a dual nickel- and photoredox-catalyzed modular approach for the preparation of enantioenriched N-benzylic heterocycles. α-Heterocyclic carboxylic acids, easily obtainable from common commercial material, are reported as suitable substrates for a decarboxylative strategy in conjunction with a chiral pyridine-oxazoline (PyOx) ligand, providing quick access to enantioenriched drug-like products. The presence of a directing group on the heterocyclic moiety is shown to be beneficial, affording improved stereoselectivity in a number of cases.
- Pezzetta, Cristofer,Bonifazi, Davide,Davidson, Robert W. M.
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supporting information
p. 8957 - 8961
(2019/11/11)
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- PLATINUM COMPOUNDS FOR BINDING GUANINE QUADRAPLEXES
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Compounds are described and characterized that bind guanine quadruplexes of DNA or RNA. Binding data and inhibition of growth data of five cancer cell lines are presented.
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(2019/06/05)
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- A new nitrogen rich open chain diazine ligand system: Synthesis coordination chemistry and magneto-structural studies
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The synthesis and coordination chemistry of a new series of open chain diazine based ligands (L3aH2, L3bH2, and L3cH2) is reported. The ligands comprise a central disubstituted bipyridine moiety with two bridging alkoxide oxygen donors, together with diazine and pyridine terminal groups strategically located to coordinate three metal centres. Reactions of L3aH2 and L3bH2 with CuX2 (X- = ClO4, Cl, NO3) yield a trinuclear complex (1) and 1-D copper chains (2, 3). In these complexes the ligands bind copper ions via Nbipyridne, trans Ndiazine, Ohydrazone, and Npyridne donors while vacant sites are occupied by counter ions or solvent molecules (methanol, water, acetonitrile). Reaction of L3cH2 with MnCl2 affords a linear trinuclear Mn complex (4), where the Mn(ii) ions are connected via μ2-Ohydrazone linkers with no N-N bridging. Reaction of L3aH2 with Fe(SO3CF3)2 yields a tetranuclear mixed valence Fe complex (5), in which both trans N-N and Ohydrazone bridging is observed. Magnetic studies reveal the presence of moderate to strong antiferromagnetic interactions in complexes 1-4 while a mix of ferromagnetic and antiferromagnetic interactions is observed in complex 5.
- Anwar, Muhammad U.,Al-Harrasi, Ahmed,Gavey, Emma L.,Pilkington, Melanie,Rawson, Jeremy M.,Thompson, Laurence K.
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p. 2511 - 2521
(2018/02/28)
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- Hydroboration Catalyzed by 1,2,4,3-Triazaphospholenes
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The synthesis and study of the catalytic activity of 1,2,4,3-triazaphospholenes (TAPs) is reported. TAPs represent a more modular scaffold than previously reported diazaphospholenes. TAP halides were shown to catalyze the 1,2 hydroboration of 19 imines, and three α,β unsaturated aldehydes with pinacolborane, including examples that did not undergo hydroboration by previously reported diazaphospholene systems. DFT calculations support a mechanism where a triazaphospholene cation interacts with the substrate, a mechanism distinct from diazaphospholene catalyzed hydroborations.
- Tien, Chieh-Hung,Adams, Matt R.,Ferguson, Michael J.,Johnson, Erin R.,Speed, Alexander W. H.
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supporting information
p. 5565 - 5568
(2017/10/25)
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- Alkali α-MnO2/Na: XMnO2 collaboratively catalyzed ammoxidation-Pinner tandem reaction of aldehydes
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The tandem reaction is a growing field to yield important advances toward green and sustainable chemistry. Herein, we report a bifunctional manganese oxide catalyst with an interface binding redox phase (α-MnO2) and a basic phase (NaxMnO2). The molar ratio of NaOH/Mn plays a great role in the formation of α-MnO2/NaxMnO2. The sodium cation is essential for the formation of a basic NaxMnO2 phase while the potassium cation promotes the formation of a redox-active α-MnO2 phase. The interface structure of α-MnO2/NaxMnO2 geometrically favors the ammoxidation-Pinner tandem reaction to synthesize imidates in a 58-96% yield from aldehydes. Thus a phase collaborative effect is observed. In the ammoxidation process, the redox cycle of MnIV/MnIII is involved and the lattice oxygen in the α-MnO2 phase acts as an active oxygen species. The O-H in methanol is activated and dissociated on the basic sites of NaxMnO2 to the adsorbed methoxyl species to facilitate the Pinner synthesis. This approach bypasses the conventional synthesis of imidates, which suffer from harsh reaction conditions and the requirement for multiple steps.
- Jia, Xiuquan,Ma, Jiping,Wang, Min,Li, Xiaofang,Gao, Jin,Xu, Jie
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p. 7429 - 7436
(2016/10/21)
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- One-pot method for synthetizing 3,5-disubstituted-1,2,4-triazole compounds
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The invention provides a one-pot method for preparing 3,5-disubstituted-1,2,4-triazole compounds shown in the general formula (I). In the general formula, at least one of X1, X2, X3 and X4 is selected from a nitrogen atom, and the others are selected from -CH; at least one of X5, X6, X7 and X8 is selected from a nitrogen atom, and the others are selected from -CH. A cascade reaction is adopted, all intermediate products are not separated or purified, that is, aromatic nitrile serving as a raw material has an addition reaction with methoxyl negative ions, and target compounds are synthetized directly under a solvothermal condition. Synthesis steps are simple, after-treatment is convenient, and large-scale production is easy to realize.
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Paragraph 0021-0024
(2017/01/23)
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- Synthesis of amidines and benzoxazoles from activated nitriles with Ni(0) catalysts
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Amidines and 2-substituted benzoxazoles were synthesized from N-heterocyclic nitriles under mild conditions (50 °C, 48 h, two steps) in an atom-economical process that involves addition of methanol, the solvent, to a nitrile moiety to yield a methyl imidate and the subsequent extrusion of solvent in the presence of amines to afford the title compounds. Methyl imidate formation was achieved by developing a new catalytic pathway using [(dippe)Ni(H)]2 (dippe = 1,2-bis(diisopropylphosphino)ethane), [Ni(cod)2]/dppe, or [Ni(cod)2]/P(OPh)3 (cod = 1,5-cyclooctadiene, dppe = 1,2-bis(diphenylphosphino)ethane, P(OPh)3 = triphenyl phosphite) as the catalyst precursor. Regarding the ligands, for a given substrate, namely 4-cyanopyridine, the best performance for the Ni(0)-catalyzed system was found for the σ-donor bidentate dippe, whereas the monodentate π acceptor P(OPh)3 was less efficient. In relation to the substrates, for a given Ni-dippe system, steric hindrance and, more importantly, substrate electron-withdrawing character control imidate formation and thus the yield of amidines and benzoxazoles.
- Gardu?o, Jorge A.,Garc?a, Juventino J.
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p. 3470 - 3477
(2015/06/16)
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- MnII- and CoII-Catalyzed Transformation of 2-Cyanopyrimidine to Methylimidate by Sodium Azide: Isolation, Structural Characterization, and Magnetic Studies on 2D MnII- and CuII-Complexes
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The MnII-mediated transformation of 2-cyanopyrimidine to methylimidate in the presence of inorganic azide is proven through isolation and structural characterization of a metal complex. Though the reaction conditions are favorable for a "click"
- Dolai, Malay,Biswas, Surajit,Escuer, Albert,Ali, Mahammad
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p. 7030 - 7037
(2015/08/03)
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- Phenylalanine-Derived Imidazolines Bearing Heteroaromatic Pendants: Synthesis, Characterization, and Application in the Asymmetric Henry Reaction
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Starting from L-phenylalanine, (2S)-3-phenylpropane-1,2-diamine has been prepared and used as building block for the construction of the imidazoline ring. Four new optically pure NH-imidazolines bearing different six-membered heteroaromatic substituents o
- Tydlitát, Ji?í,Bure?, Filip,R??i?ková, Zdeňka
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p. 1351 - 1363
(2015/10/28)
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- Organic carbonate synthesis from CO2 and alcohol over CeO 2 with 2-cyanopyridine: Scope and mechanistic studies
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The combination system of CeO2-catalyzed carboxylation and 2-cyanopyridine hydration (CeO2 + 2-cyanopyridine system) is effective for the direct synthesis of organic carbonates from CO2 and alcohols. This catalyst system can be applied to various alcohols to afford the corresponding carbonates in high alcohol-based yields. The hydration of 2-cyanopyridine over CeO2 rapidly proceeds under the low concentration of water, which can remove the water from the reaction media. Since the reaction is limited by the chemical equilibrium, the removal of water remarkably shifts the chemical equilibrium to the carbonate side, leading to high carbonate yields. In addition, 2-picolinamide that is produced by hydration of 2-cyanopyridine forms an intramolecular hydrogen bonding between H atom of the amide group and N atom of the pyridine ring, which weakens the adsorption of 2-picolinamide on CeO2 by reduction of the acidity. The reaction mechanism of DMC formation in CeO2 + 2-cyanopyridine system is also proposed.
- Honda, Masayoshi,Tamura, Masazumi,Nakagawa, Yoshinao,Nakao, Kenji,Suzuki, Kimihito,Tomishige, Keiichi
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- Iron(II)-catalyzed intramolecular olefin aminofluorination
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An iron(II)-catalyzed diastereoselective olefin aminofluorination is reported (dr up to >20:1). This new transformation applies a functionalized hydroxylamine and Et3N·3HF as the nitrogen and fluorine source, which facilitates the efficient synthesis of β-fluoro primary amines and amino acids from allylic alcohol derivatives. Preliminary mechanistic studies reveal that an iron-nitrenoid is a possible intermediate and that its reactivity and enantioselectivity can be efficiently modulated by ligands.
- Lu, Deng-Fu,Liu, Guan-Sai,Zhu, Cheng-Liang,Yuan, Bo,Xu, Hao
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supporting information
p. 2912 - 2915
(2014/06/23)
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- Chemoselective oxidation of polyols with chiral palladium catalysts
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Chiral palladium-based catalysts derived from pyridinyl oxazoline (pyOx) ligands catalyze the oxidation of alcohols, including 1,2-diols, triols, and tetraols, with high regio- and chemoselectivity. Screening of various chiral oxazoline-derived ligands for the oxidation of a model diol, 1,2-propanediol (1,2-PD), revealed that the nature of the ligand had a significant influence on the activity and chemoselectivity for oxidation of vicinal diols. The PyOx ligands containing an α-methyl substituent were the most active for the oxidation of 1,2-PD using benzoquinone as the terminal oxidant. Oxidation of vicinal diols and polyols occurs selectively at the secondary alcohol to afford α-hydroxy ketones in isolated yields of 62-87%. Chemoselective oxidation of meso-erythritol with the chiral [(S)-(α-Me(tert-Bu)PyOx)Pd(OAc)] 2[OTf]2 afforded (S)-erthyrulose in 62% yield and 24% ee.
- De Crisci, Antonio G.,Chung, Kevin,Oliver, Allen G.,Solis-Ibarra, Diego,Waymouth, Robert M.
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p. 2257 - 2266
(2013/05/21)
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- Synthesis and characterization of blue-to-green electrophosphorescence emitter based on pyrazole iridium complexes
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To overcome the roll-off efficiency of electrophosphorescent organic light-emitting devices, Ir(III) complexes of (ppz)2Ir(N?N) were synthesized and named for (ppz)2Ir(tfmpptz), (ppz) 2Ir(fpptz), (ppz)2Ir(tfmptz) and (ppz)2Ir(pybi) (ppz: 1-phenylpyrazolato; N?N: N, N′-heteroaromatic). Their molecular structures, photophysical properties and cyclic voltammetric data were reported. The crystals of (ppz)2Ir(tfmpptz), (ppz) 2Ir(fpptz) are monoclinic, space group P2(1)/n, and (ppz) 2Ir(tfmptz) is triclinic, space group P-1. The emission maximum peaks of (ppz)2Ir(tfmpptz), (ppz)2Ir(fpptz), (ppz) 2Ir(tfmptz) and (ppz)2Ir(pybi) at room temperature appear at 486, 497, 473 and 530 nm, respectively. The devices with architecture of ITO/NPB (30 nm)/CBP: (ppz)2Ir(N?N) (6%, 30 nm)/BAlq(10 nm)/Alq3(30 nm)/LiF(1 nm)/Al (100 nm) were fabricated by thermal evaporation. The results indicate that the larger steric hindrance of ancillary ligands efficiently suppressed the roll-off of efficiency at high current density.
- Huixia, Xu,Yan, Yue,Litao, Qu,Yuying, Hao,Hua, Wang,Liuqing, Chen,Bingshe, Xu
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- Mechanism and enantioselectivity in palladium-catalyzed conjugate addition of arylboronic acids to β-substituted cyclic enones: Insights from computation and experiment
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Enantioselective conjugate additions of arylboronic acids to β-substituted cyclic enones have been previously reported from our laboratories. Air- and moisture-tolerant conditions were achieved with a catalyst derived in situ from palladium(II) trifluoroacetate and the chiral ligand (S)-t-BuPyOx. We now report a combined experimental and computational investigation on the mechanism, the nature of the active catalyst, the origins of the enantioselectivity, and the stereoelectronic effects of the ligand and the substrates of this transformation. Enantioselectivity is controlled primarily by steric repulsions between the t-Bu group of the chiral ligand and the α-methylene hydrogens of the enone substrate in the enantiodetermining carbopalladation step. Computations indicate that the reaction occurs via formation of a cationic arylpalladium(II) species, and subsequent carbopalladation of the enone olefin forms the key carbon-carbon bond. Studies of nonlinear effects and stoichiometric and catalytic reactions of isolated (PyOx)Pd(Ph)I complexes show that a monomeric arylpalladium-ligand complex is the active species in the selectivity-determining step. The addition of water and ammonium hexafluorophosphate synergistically increases the rate of the reaction, corroborating the hypothesis that a cationic palladium species is involved in the reaction pathway. These additives also allow the reaction to be performed at 40 C and facilitate an expanded substrate scope.
- Holder, Jeffrey C.,Zou, Lufeng,Marziale, Alexander N.,Liu, Peng,Lan, Yu,Gatti, Michele,Kikushima, Kotaro,Houk,Stoltz, Brian M.
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supporting information
p. 14996 - 15007
(2013/11/06)
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- Palladium-catalyzed asymmetric conjugate addition of arylboronic acids to heterocyclic acceptors
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Flava Flavanone: Asymmetric conjugate additions to chromones and 4-quinolones are reported utilizing a single catalyst system formed in situ from Pd(OCOCF3)2 and (S)-tBuPyOX. Notably, these reactions are performed in wet solvent under ambient atmosphere, and employ readily available arylboronic acids as the nucleophile, thus providing ready access to these asymmetric heterocycles (see scheme).
- Holder, Jeffrey C.,Marziale, Alexander N.,Gatti, Michele,Mao, Bin,Stoltz, Brian M.
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supporting information
p. 74 - 77
(2013/02/25)
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- Synthesis, structure, and biological activity of novel heterocyclic sulfonyl-carboximidamides
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A series of novel heterocyclic sulfonyl-carboximidamides were synthesized in satisfactory yields via condensation of heterocyclic methyl carbimidates with 2-chlorobenzenesulfonamide and 4-chloropyridine-3-sulfonamide. New structures were confirmed by IR and NMR spectra as well as elemental analyses. X-ray crystallography of two derivatives was performed. The single-crystal structures confirmed the presence of a primary amine group in the amidine moiety. All the compounds were screened for their tuberculostatic, antibacterial, and anticancer activities. Preliminary results indicated that target compounds exhibited weak tuberculostatic and antibacterial activities. Seven compounds inhibited the growth of some cancer cell lines, whereas one of the 2-quinoline derivatives displayed favorable activity against all tested cancer cells with GI 50 values of 0.92-13 μM.
- Gobis, Katarzyna,Foks, Henryk,Slawinski, Jaroslaw,Sikorski, Artur,Trzybinski, Damian,Augustynowicz-Kopec, Ewa,Napiorkowska, Agnieszka,Bojanowski, Krzysztof
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p. 647 - 658
(2013/07/26)
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- A scalable synthesis of the (S)-4-(tert-butyl)-2-(pyridin-2-yl)-4,5- dihydrooxazole ((S)-t-BuPyOx) ligand
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An efficient method for the synthesis of the (S)-4-(tert-butyl)-2-(pyridin- 2-yl)-4,5-dihydrooxazole ((S)-t-BuPyOx) ligand has been developed. Inconsistent yields and tedious purification in known routes to (S)-t-BuPyOx suggested the need for an efficient, dependable, and scalable synthetic route. Furthermore, a route suitable for the synthesis of PyOx derivatives is desirable. Herein, we describe the development of a three-step route from inexpensive and commercially available picolinic acid. This short procedure is amenable to multi-gram scale synthesis and provides the target ligand in 64% overall yield.
- Shimizu, Hideki,Holder, Jeffrey C.,Stoltz, Brian M.
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supporting information
p. 1637 - 1642
(2013/10/22)
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- PROTEIN KINASE INHIBITORS AND METHODS OF TREATMENT
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The present invention relates to chemical compounds of formula (I) and methods for their use and preparation. In particular, the invention relates to substituted pyrazolo[3,4-d]pyrimidine based compounds which can be used in treating proliferative disorders, use of these compounds in methods of therapy and the manufacture of medicaments as well as compositions containing these compounds.
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Page/Page column 87-88
(2012/02/01)
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- The use of a versatile o-vanilloyl hydrazone ligand to prepare SMM-like Dy3 molecular cluster pair
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A novel lanthanide molecular cluster pair (MCP), displaying single molecule magnet behaviour, was assembled using the novel o-vanilloyl hydrazone ligand, versatile in terms of denticity, tautomerism and the rotatable C-C bond.
- Xue, Shufang,Zhao, Lang,Guo, Yun-Nan,Zhang, Peng,Tang, Jinkui
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supporting information
p. 8946 - 8948
(2012/11/13)
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- New potent 5-HT2A receptor ligands containing an N′-cyanopicolinamidine nucleus: Synthesis and in vitro pharmacological evaluation
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N′-cyanopicolinamidine derivatives, linked to an arylpiperazine moiety, were prepared and their affinity to serotonin 5-HT1A, 5-HT2A and 5-HT2C receptors were evaluated. The combination of structural elements (heterocyclic
- Fiorino, Ferdinando,Severino, Beatrice,Magli, Elisa,Perissutti, Elisa,Frecentese, Francesco,Esposito, Antonella,Incisivo, Giuseppina Maria,Ciano, Antonio,Massarelli, Paola,Nencini, Cristina,Santagada, Vincenzo,Caliendo, Giuseppe
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experimental part
p. 520 - 529
(2012/03/11)
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- Catalyst development for organocatalytic hydrosilylation of aromatic ketones and ketimines
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A new family of Lewis basic 2-pyridyl oxazolines have been developed, which can act as efficient organocatalysts for the enantioselective reduction of prochiral aromatic ketones and ketimines with trichlorosilane, a readily available and inexpensive reagent. 1-Isoquinolyl oxazoline, derived from mandelic acid, was identified as the most efficient catalyst of the series, capable of delivering high enantioselectivities in the reduction of both ketones (up to 94% ee) and ketimines (up to 89% ee).
- Malkov, Andrei V.,Stewart-Liddon, Angus J. P.,McGeoch, Grant D.,Ramirez-Lopez, Pedro,Kocovsky, Pavel
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scheme or table
p. 4864 - 4877
(2012/07/28)
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- Camphor-annelated imidazolines with various N1 and C2 pendants as tunable ligands for nitroaldol reactions
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Starting from (1R,2S,3R)-camphordiamine and (hetero)aromatic imidates and orthoformate, nine new camphor-annelated NH-imidazolines were synthesized. Subsequent N-modification was carried out via methylation, acylation, benzoylation, and sulfonylation. Two regioisomers were usually isolated with the ratios reflecting the structure of the starting NH-imidazoline and the electrophile used. All of the successfully prepared N1- and C2-substituted camphor-annelated imidazolines were applied to the asymmetric version of a Cu(II)-catalyzed Henry reaction. The electronic effects of both N1- and C2-pendants on the chemical and asymmetric outcomes of the nitroaldol reaction have been studied and discussed. 2012 Elsevier Ltd.
- Tydlitat, Jiri,Bures, Filip,Kulhanek, Jiri,Mloston, Grzegorz,Ruzicka, Ales
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experimental part
p. 1010 - 1018
(2012/09/25)
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- Synthesis, structure, and antimicrobial activity of heterocyclic phenylsulfonyl- and 4-aminophenylsulfonyl-carboximidamides
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A series of novel phenylsulfonyl- and 4-amino-phenylsulfonyl- carboximidamides were synthesized by condensation of sulfonamides with heterocyclic methyl carbimi-dates obtained from heterocyclic carbonitriles and used 'at its inception.' The molecular structure of the obtained compounds is discussed. Compounds possessing heterocyclic systems with a nitrogen atom in the α position to the functional group showed a different single-crystal structure than expected. The synthesized derivatives were evaluated for antimicrobial activities: tuberculostatic, antibacterial, and antifungal.
- Gobis, Katarzyna,Foks, Henryk,Wisniewska, Katarzyna,Dabrowska-Szponar, Maria,Augustynowicz-Kopec, Ewa,Napiorkowska, Agnieszka,Sikorski, Artur
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experimental part
p. 1161 - 1169
(2012/10/08)
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- Synthesis and antimicrobial activity of novel heterocyclic sulfamoyl-phenyl-carboximidamides derived from clinically applied sulfonamides
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A series of novel heterocyclic sulfamoyl-phenyl-carboximidamides were synthesized in satisfactory yields via condensation of clinically applied sulfonamides with heterocyclic methyl carbimidates. New structures were confirmed by IR and NMR spectra as well as elemental analyses. All the compounds were screened for their antibacterial, antifungal, and tuberculostatic activities. Preliminary results indicated that some target compounds exhibited promising antibacterial potency. Especially, N-[4-(thiazol-2-sulfamoyl)phenyl] pyrazine-2-carboximidamide (16) was found to be as potent as clinically applied sulfamethoxypyridazine. Copyright
- Gobis, Katarzyna,Foks, Henryk,Wisniewska, Katarzyna,Dabrowska-Szponar, Maria,Augustynowicz-Kopec, Ewa,Napiorkowska, Agnieszka
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p. 911 - 917
(2013/01/15)
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- Palladium-catalyzed asymmetric conjugate addition of arylboronic acids to five-, six-, and seven-membered β-substituted cyclic enones: enantioselective construction of all-carbon quaternary stereocenters
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The first enantioselective Pd-catalyzed construction of all-carbon quaternary stereocenters via 1,4-addition of arylboronic acids to β-substituted cyclic enones is reported. Reaction of a wide range of arylboronic acids and cyclic enones using a catalyst
- Kikushima, Kotaro,Holder, Jeffrey C.,Gatti, Michele,Stoltz, Brian M.
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supporting information; experimental part
p. 6902 - 6905
(2011/06/19)
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- CuI-catalyzed hydroxylation of aryl bromides under the assistance of 5-bromo-2-(1H-imidazol-2-yl)pyridine and related ligands
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A number of substituted 2-pyridin-2-yl-1H-benzoimidazoles and 2-(1H-imidazol-2-yl)pyridines were screened for promoting CuI-catalyzed hydroxylation of aryl bromides, which led to the discovery of the combination of CuI and 5-bromo-2-(1H-imidazol-2-yl)pyridine as an effective catalytic system for this transformation. Both electron-rich and electronic-deficient aryl bromides could be converted into the corresponding substituted phenols in good to excellent yields.
- Jia, Jianhuan,Jiang, Chenglin,Zhang, Xiaojing,Jiang, Yongwen,Ma, Dawei
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supporting information; experimental part
p. 5593 - 5595
(2011/11/06)
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- 1,2-disubstituted hexahydro-1 H -benzo[d]imidazoles: Synthesis, characterization, and stability
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Starting from commercially available (hetero)aromatic nitriles and (1R,2R)-cyclohexane-1,2-diamine, nine NH-imidazolines (hexahydro-1H-benzo[d] imidazoles) were synthesized in good yields. The molecular structures of three imidazolines were confirmed by X-ray analysis. N-Benzylation afforded some of the desired N-benzylimidazolines, but was incompatible with imidazolines that possessed strong electron-accepting heteroaromatic groups at C2. In the latter cases, the products decomposed during column chromatography to form N,N-disubstituted cyclohexane-1,2-diamines. Georg Thieme Verlag Stuttgart · New York.
- Tydlitat, Jiri,Bures, Filip,Kulhanek, Jiri,Ruzicka, Ales
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experimental part
p. 3934 - 3940
(2010/12/29)
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- Pyrrolopyrimidines and Pyrrolopyridines
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Compounds of formula I in free or salt or solvate form, wherein X, T1, T3 and T4 have the meanings as indicated in the specification, are useful for treating diseases mediated by the ALK-5 and/or ALK-4 receptor. Pharmaceutical compositions that contain the compounds and processes for preparing the compounds are also described.
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Page/Page column 45-46
(2009/07/25)
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- Probing electronic and regioisomeric control in an asymmetric Henry reaction catalyzed by camphor-imidazoline ligands
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Starting from (R)-camphordiamine, 13 new camphor-annulated imidazoline ligands are synthesized in good yields as two regioisomeric series. Yields of up to 94% and good enantioselectivities up to 67% are achieved for the copper(II)-catalyzed Henry reaction
- Bure?, Filip,Kulhánek, Ji?í,R??i?ka, Ale?
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supporting information; experimental part
p. 3042 - 3045
(2009/10/04)
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- Facile synthesis of 6-aryl-3-pyridyl-1,2,4-triazines as a key step toward highly fluorescent 5-substituted bipyridines and their Zn(II) and Ru(II) complexes
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A wide series of substituted bipyridines were obtained through the synthesis of 1,2,4-triazines and their aza Diels-Alder reactions. The reported method facilitates the synthesis of functionally diverse bipyridines that provides fine-tuning of photophysical properties of new ligands and their Zn(II) and Ru(II) complexes. Some of substituted bipyridines exhibit 'off-on' fluorescence response toward Zn2+ cations.
- Kozhevnikov, Valery N.,Shabunina, Olga V.,Kopchuk, Dmitry S.,Ustinova, Maria M.,K?nig, Burkhard,Kozhevnikov, Dmitry N.
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p. 8963 - 8973
(2008/12/22)
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- A simple and convenient one-pot method for the preparation of heteroaryl-2-imidazoles from nitriles
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A simple, convenient and high-yielding one-pot method for the synthesis of 2-heterocycle-substituted imidazoles from the corresponding nitriles has been developed. The procedure is easily scaleable and the workup does not involve chromatography. This synthesis is also applicable to the preparation of imidazoles with electron-poor aryl substituents.
- Voss, Matthew E.,Beer, Catherine M.,Mitchell, Scott A.,Blomgren, Peter A.,Zhichkin, Paul E.
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p. 645 - 651
(2008/04/12)
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- Synthesis and evaluation of adenosine antagonist activity of a series of [1,2,4]triazolo[1,5-c]quinazolines
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A series of [1,2,4]triazolo[1,5-c]quinazolines were prepared in satisfactory yields by reaction of some derivatives of 2-aminobenzohydrazide with several hydrochlorides of aromatic amidines, and their binding affinities for the recombinant human adenosine A2A and A2B receptors were determined. None of the new compounds showed noteworthy affinity for these receptors, though a very high affinity for the A2A receptor and, consequently, a high level of A2A/A2B selectivity was revealed for one of the synthesized compounds.
- Balo, Carmen,Lopez, Carmen,Brea, Jose Manuel,Fernandez, Franco,Caamano, Olga
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p. 372 - 375
(2008/02/02)
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- Remote chiral induction in the organocatalytic hydrosilylation of aromatic ketones and ketimines
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(Chemical Equation Presented) Lewis basic, metal-free pyridyloxazolines catalyze the reduction of prochiral aromatic ketones and ketimines with Cl 3SiH in good enantioselectivity (up to 94% ee). Arene-arene interactions between the substrate and the catalyst are likely to play a role in the enantiodifferentiation process.
- Malkov, Andrei V.,Stewart Liddon, Angus J. P.,Ramirez-Lopez, Pedro,Bendova, Lada,Haigh, David,Kocovsky, Pavel
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p. 1432 - 1435
(2007/10/03)
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- Synthesis, anti-inflammatory and analgesic activity evaluation of some amidine and hydrazone derivatives
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A number of amidine derivatives (3a-i) were synthesized by condensation of cyanopyridine and cyanopyrazine with sulfonylhydrazides in the presence of sodium methoxide. 2-Acetylpyridine and 4-acetylpyridine were condensed with sulfonylhydrazides by microwa
- Sondhi, Sham M.,Dinodia, Monica,Kumar, Ashok
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p. 4657 - 4663
(2007/10/03)
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