- Cyclotriveratrylene-tethered trinuclear palladium(ii)-NHC complexes; Reversal of site selectivity in Suzuki-Miyaura reactions
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The trinuclear complexes [{PdI2(pyCl)}3(L1)] C1 and [{PdI2(pyCl)}3(L2)] C2, where pyCl = 3-chloropyridine, L1 = methyl(cyclotriguaiacylenyl)methylbenzimidazol-2-ylidene and L2 = benzyl(cyclotriguaiacylenyl)methy
- Fowler, Jonathan M.,Britton, Edward,Pask, Christopher M.,Willans, Charlotte E.,Hardie, Michaele J.
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- An efficient water-soluble surfactant-type palladium catalyst for Suzuki cross-coupling reactions in pure water at room temperature
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A palladium catalyst based on a bidentate phosphine-type zwitterionic surfactant as a ligand exhibited an excellent catalytic activity in the Suzuki-Miyaura cross coupling reactions. This novel method allowed the reaction of aryl halides with arylboronic acids to occur in pure water at room temperature, forming a variety of biaryls in good to high yields. Heterobiaryls were also efficiently assembled even in the presence of water-insoluble heteroaryl halides as substrates. In addition, such a coupling protocol was successfully used in the iterative diarylation of 2,5-dibromopyridine in one-pot.
- Qiu, Pei,Zhao, Jing Yang,Shi, Xu,Duan, Xin Hong
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supporting information
p. 6568 - 6572
(2016/08/10)
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- Selective palladium-catalysed arylation of 2,6-dibromopyridine using N-heterocyclic carbene ligands
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A selective palladium-catalysed arylation of 2,6-dibromopyridine has been developed by employing N-heterocyclic carbene ligands. Selective mono-arylation was performed in water/acetonitrile solvent system at ambient temperature with catalyst loading of 0.1 mol%. This reaction was also found to proceed smoothly in water although at a slightly elevated temperature of 80 °C. 2,6-Disubstituted and diversely substituted 2,6-pyridines were also obtained in high yields which will be of importance to organic and medicinal chemists.
- Prajapati,Schulzke,Kindermann,Kapdi
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p. 53073 - 53085
(2015/06/25)
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- Cross-coupling study of iodo/chloropyridines and 2-chloroquinoline with atom-economic triarylbismuth reagents under Pd-catalysis
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This study describes the palladium-catalyzed couplings of iodopyridines, chloropyridines, and chloroquinoline with atom-economic BiAr3 reagents in sub-stoichiometric loadings. Mono-arylations of iodo and chloropyridines produced arylpyridines i
- Rao, Maddali L.N.,Dhanorkar, Ritesh J.
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p. 338 - 349
(2015/03/04)
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- Triarylbismuthanes as threefold aryl-transfer reagents in regioselective cross-coupling reactions with bromopyridines and quinolines
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Cross-coupling studies using bromopyridines and bromoquinolines with triarylbismuths as threefold coupling reagents in substoichiometric amounts under Pd-catalysed conditions are disclosed. The reactivity was high with both mono- and dibromopyridyl substrates, and mono- and bis-couplings were carried out regioselectively. A library of monoaryl and diaryl pyridines was formed in high yields. A one-pot strategy provided a simple and straightforward synthesis of both symmetrical and unsymmetrical diarylpyridines. Arylations of 2-bromo- and 3-bromoquinolines were achieved with triarylbismuth reagents. This study demonstrates that triarylbismuths may be used as threefold arylating reagents for the synthesis of aryl pyridines and quinolines through couplings with bromopyridines and bromoquinolines under Pd-catalysed conditions. Copyright
- Rao, Maddali L.N.,Dhanorkar, Ritesh J.
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supporting information
p. 5214 - 5228
(2014/10/15)
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- Palladium-catalyzed highly regioselective 2-arylation of 2,x-dibromopyridines and its application in the efficient synthesis of a 17β-HSD1 inhibitor
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2,3- and 2,5-Dibromopyridines reacted with arylboronic acids, catalyzed by Pd(OAc)2/PPh3 in the presence of K2CO 3 in CH3CN/MeOH (2:1) at 50 C for 24 h, to afford 2-arylpyridines in good to high yield
- Zhou, Qizhong,Zhang, Bin,Su, Liangjun,Jiang, Tiansheng,Chen, Rener,Du, Tieqi,Ye, Yuyuan,Shen, Jianfen,Dai, Guoliang,Han, Deman,Jiang, Huajiang
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p. 10996 - 11003
(2014/01/06)
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- Substituted Benzo-Imidazo-Pyrido-Diazepine Compounds
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The present invention relates to substituted benzo-imidazo-pyrido-diazepine compounds and methods of synthesizing these compounds. The present invention also relates to pharmaceutical compositions containing substituted benzo-imidazo-pyrido-diazepine compounds and methods of treating cell proliferative disorders, such as cancer, by administering these compounds and pharmaceutical compositions to subjects in need thereof.
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Page/Page column 132
(2012/05/07)
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- Virtual screening and optimization yield low-nanomolar inhibitors of the tautomerase activity of Plasmodium falciparum macrophage migration inhibitory factor
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The Plasmodium falciparum orthologue of the human cytokine, macrophage migratory inhibitory factor (PfMIF), is produced by the parasite during malaria infection and modulates the host's immune response. As for other MIF orthologues, PfMIF has tautomerase activity, whose inhibition may influence the cytokine activity. To identify small-molecule inhibitors of the tautomerase activity of PfMIF, virtual screening has been performed by docking 2.1 million compounds into the enzymatic site. Assaying of 17 compounds identified four as active. Substructure search for the most potent of these compounds, a 4-phenoxypyridine analogue, identified four additional compounds that were purchased and also shown to be active. Thirty-one additional analogues were then designed, synthesized, and assayed. Three were found to be potent PfMIF tautomerase inhibitors with Ki of ~40 nM; they are also highly selective with Ki > 100 μM for human MIF.
- Dahlgren, Markus K.,Garcia, Alvaro Baeza,Hare, Alissa A.,Tirado-Rives, Julian,Leng, Lin,Bucala, Richard,Jorgensen, William L.
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supporting information
p. 10148 - 10159
(2013/01/16)
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- 5-Bromo-2-pyridylzinc reagent; Direct preparation and its coupling reactions
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A facile synthetic route to the direct preparation of 5-bromo-2-pyridylzinc iodide has been developed. Treatment of 5-bromo-2-iodopyridine with active zinc gave rise to the selective oxidative addition to C-I bond under mild conditions. The resulting orga
- Rieke, Reuben D.,Kim, Seung-Hoi
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supporting information; experimental part
p. 244 - 247
(2011/02/25)
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- Disubstituted pyridines: The double-coupling approach
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(Chemical Equation Presented) A one-pot procedure leading to disubstituted pyridines from the starting dibromopyridines is described. Key features include the ability to couple a range of aryl and even alkenylboronic acids at the 2,3 and/or 2,5 positions
- Handy, Scott T.,Wilson, Thomas,Muth, Aaron
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p. 8496 - 8500
(2008/02/13)
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- Regioselective Arylation of 3-Bromopyridine
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The addition of aryl Grignard reagents to the 1-phenoxycarbonyl salt of 3-bromopyridine affords 2-aryl-5-bromo-1-phenoxycarbonyl-1,2-dihydropyridines and 4-aryl-3-bromo-1-phenoxycarbonyl-1,4-dihydropyridines.The crude dihydropyridines were aromatized with o-chloranil in refluxing toluene to give 4- and 6-aryl-3-bromopyridines.The regioselectivity of this two-step process, 6- vs. 4-substitution, was examined and found to be dependent upon the structure of the Grignard reagent.Unhindered aryl Grignard reagents, e.g., phenyl and 2-naphthyl, gave mainly 6-aryl-3-bromopyridines (49-52percent) along with 9percent of the 4-substituted isomer and less than 4percent of the 2-aryl-3-bromopyridine.Hindered aryl Grignard reagents, e.g., o-tolyl and 1-naphthyl, are less regioselective.When a catalytic amount of cuprous iodide is present during the Grignard reaction, nearly exclusive 1,4-addition results.The crude 4-aryl-3-bromo-1,4-dihydropyridines were aromatized with p-chloranil to provide 4-aryl-3-bromopyridines in good yield and high isomeric purity.The sequential use of the cuprous iodide-catalyzed Grignard reaction and the "normal" Grignard reaction provided a regiospecific synthesis of 3-bromo-6-(p-methoxyphenyl)-4-phenylpyridine from 3-bromopyridine.
- Comins, Daniel L.,Mantlo, Nathan B.
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p. 1239 - 1243
(2007/10/02)
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