- Ru-catalyzed β-selective and enantioselective addition of amines to styrenes initiated by direct arene-exchange
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A catalytic β-selective addition of amines to styrenes proceeded in the presence of cationic Ru complexes combined with diphosphine ligands. In the reaction of α-methylstyrene, an enantioselective addition was achieved by using xylylBINAP.
- Otsuka, Maiko,Yokoyama, Hiroya,Endo, Kohei,Shibata, Takanori
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scheme or table
p. 3815 - 3818
(2012/06/04)
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- Discovery of LASSBio-772, a 1,3-benzodioxole N-phenylpiperazine derivative with potent alpha 1A/D-Adrenergic receptor blocking properties
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We described herein the discovery of 1-(2-(benzo[d] [1,3]dioxol-6-yl)ethyl) -4-(2-methoxyphenyl) piperazine (LASSBio-772), as a novel potent and selective alpha 1A/1D adrenoceptor (AR) antagonist selected after screening of functionalized N-phenylpiperazine derivatives in phenylephrine-induced vasoconstriction of rabbit aorta rings. The affinity of LASSBio-772 for alpha 1A and alpha 1B AR subtypes was determined through displacement of [ 3H]prazosin binding. We obtained Ki values of 0.14 nM for the alpha 1A-AR, similar to that displayed by tamsulosin (Ki = 0.13 nM) and 5.55 nM for the alpha 1B-AR, representing a 40-fold higher affinity for alpha 1A-AR. LASSBio-772 also presented high affinity (KB = 0.025 nM) for the alpha 1D-AR subtype in the functional rat aorta assay, showing to be equipotent to tamsulosin (KB = 0.017 nM).
- Romeiro, Luiz A.S.,Da Silva Ferreira, Marcos,Da Silva, Leandro L.,Castro, Helena C.,Miranda, Ana L.P.,Silva, Cláudia L.M.,No?l, Franois,Nascimento, Jéssica B.,Araújo, Claudia V.,Tibiri?á, Eduardo,Barreiro, Eliezer J.,Fraga, Carlos A.M.
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p. 3000 - 3012
(2011/07/08)
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- Straightforward three-component synthesis of diarylmethylpiperazines and 1,2-diarylethylpiperazines
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Several functionalized diarylmethylpiperazines and 1,2-diarylethylpiperazines have been synthesized in moderate to high yield according to a one-step three-component coupling between an aromatic or a benzylic organozinc reagent, a piperazine derivative, and an aromatic aldehyde. The procedure can be extended to the synthesis of benzylpiperazine derivatives or β-arylethylpiperazines toward the use of paraformaldehyde or aliphatic aldehydes.
- Sengmany, Stéphane,Le Gall, Erwan,Le Jean, Cédric,Troupel, Michel,Nédélec, Jean-Yves
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p. 3672 - 3681
(2007/10/03)
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- RUTHENIUM-CATALYZED HYDROAMINATION OF OLEFINS
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Applicants have unexpectedly discovered that catalysts made from a ruthenium catalyst precursor or preformed ruthenium catalysts as otherwise described in the present specification are capable of effecting the addition of a N-H bond across an olefin C=C (olefinic) bond of a substrate with a high degree of regioselectivity and enantioselectivity in high yield. These addition reactions proceed in an anti-Markovnikov or Markovnikov fashion depending upon the catalyst precursor used to generate the ruthenium catalyst which actually participates in the addition reaction. The present invention relates to methods of adding N-H bonds across an olefinic bond in a substrate, using a ruthenium catalyst precursor or catalyst I comprising a compound according to the general structure I: Formula (I) where Ru is a ruthenium atom; L1 represents one or more coordinated ancillary ligands, which may be all the same ligand or which may be a combination of different ligands, each of which may be neutral or formally charged, and each of which may be monodentate and coordinated to ruthenium through a single atom or which may be linked or chelated and bound through more than one atom; L2 represents one or more formally charged ligands which are the same or different and which are optionally susceptible to removal with a strong acid; and x is 0-6, preferably 1, y is 0-6, preferably 2 and n is 1-4, preferably 1.
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Page/Page column 20-21; 30
(2010/02/13)
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- Interaction of arylpiperazines with the dopamine receptor D2 binding site
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The docking of several 1-benzyl-4-arylpiperazines to the dopamine receptor (DAR) D2 was examined. The results demonstrated that the interaction of protonated N1 of the piperazine ring with Asp 86 (III.32) and edge-to-face interactions of the aromatic ring of the arylpiperazine part of the ligand with Phe 178 (VI.44), Trp 182 (VI.48) and Tyr 216 (VII.58) of the receptor, represent the major stabilizing forces. Besides, the hydrogen bond acceptor group in position 2 of the phenylpiperazine aromatic ring could build one more hydrogen bond with Trp 182 (VI.48). Bulky substituents in position 4 were not tolerated due to the unfavorable sterical interaction with Phe 178 (VI.44). Substituents in position 2 and 3 were found to be sterically well tolerated. Introduction of electron attractive -NO2 group in position 3 of arylpiperazines decreased, while electron donors (-OMe) and the second aromatic ring (naphthyl) increased the binding affinity comparing to that of the phenylpiperazine 1. This can be explained in terms of favoured edge-to-face interactions in ligands with a high negative electrostatic surface potential (ESP) in the centre of aromatic residue of arylpiperazines. Thus, besides the salt bridges and hydrogen bonds, edge-to-face interactions significantly contribute to arylpiperazine ligands to form complexes with the DAR D2. Phe 178 (VI.44), Trp 182 (VI.48) and Tyr 216 (VII.58) can be considered as a part of the ancillary DAR D2 pocket preserved in most G protein-coupled receptors of the A class and obviously, the arylpiperazine structural motif represents one of the privileged structures that bind to this pocket.
- Sukalovic, Vladimir,Zlatovic, Mario,Andric, Deana,Roglic, Goran,Kostic-Rajacic, Sladjana,Soskic, Vukic
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p. 145 - 152
(2007/10/03)
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- Ruthenium-Catalyzed Anti-Markovnikov Hydroamination of Vinylarenes
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A ruthenium-catalyzed intermolecular, anti-Markovnikov hydroamination of vinylarenes with secondary aliphatic and benzylic amines is reported. The combination of Ru(cod)(2-methylallyl)2, 1,5-bis(diphenylphosphino)pentane, and triflic acid was the most effective catalyst of those tested. Control reactions conducted without ligand or acid did not form the amine. The reaction of morpholine, piperidine, 4-phenylpiperazine, 4-BOC-piperazine, 4-piperidone ethylene ketal, and tetrahydroisoquinoline with styrene in the presence of 5 mol % of this catalyst formed the corresponding β-phenethylamine products in 64?96% yield, with 99% regioselectivity, and without enamine side products. Acyclic amines such as n-hexylmethylamine and N-benzylmethylamine reacted with styrene in 63 and 50% yields, respectively. Alkyl-, methoxy-, and trifluoromethyl-substituted styrenes reacted with morpholine in the presence of this catalyst or a related one containing 1,1′-bis(diisopropylphosphino)ferrocene as ligand to give the products in 51?91%. Further, the hydroamination of α-methyl styrene was observed for the first time with a homogeneous transition metal catalyst. Preliminary mechanistic studies showed that the reaction occurred by direct, irreversible, anti-Markovnikov hydroamination and that the mechanism of the ruthenium-catalyzed hydroamination is likely to be distinct from that of the recently reported rhodium-catalyzed reaction. Copyright
- Utsunomiya, Masaru,Hartwig, John F.
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p. 2702 - 2703
(2007/10/03)
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- INHIBITORS OF FUNGAL INVASION
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This invention relates to various anti-fungall agents including agents that are inhibitors of fungal invasion.
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Drawing sheet 10
(2010/02/09)
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- Rhodium-catalyzed anti-Markovnikov hydroamination of vinylarenes
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The transition metal-catalyzed anti-Markovnikov hydroamination of unactivated vinylarenes with a rhodium complex of DPEphos is reported. The reaction of electron-neutral or electron-rich vinylarenes with a variety of secondary amines in the presence of catalyst forms the products from anti-Markovnikov hydroamination in high yields. Reactions of morpholine, N-phenylpiperazine, N-Boc-piperazine, piperidine, 2,5-dimethylmorpholine, and perhydroisoquinoline reacted with styrene to form the amine product in 51-71% yield. Reactions of a variety of vinylarenes with morpholine generated amine as the major product. Reactions of morpholine with electron-poor vinylarenes gave lower amine:enamine ratios than reactions of electron-rich vinylarenes at the same concentration of vinylarene, but conditions were developed with lower concentrations of electron-poor vinylarene to maintain formation of the amine as the major product. Reactions of dimethylamine with vinylarenes were fast and formed amine as the major product. Mechanistic studies on the hydroamination process showed that the amine:enamine ratio was lower for reactions conducted with higher concentrations of vinylarene and that one vinylarene influences the selectivity for reaction of another. A mechanism proceeding through a metallacyclic intermediate that opens in the presence of a second vinylarene accounts for these and other mechanistic observations. Copyright
- Utsunomiya, Masaru,Kuwano, Ryoichi,Kawatsura, Motoi,Hartwig, John F.
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p. 5608 - 5609
(2007/10/03)
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