- Geometric control of nuclearity in copper(I)/dioxygen chemistry
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Copper(I) complexes supported by a series of N3-tridentate ligands bearing a rigid cyclic diamine framework such as 1,5-diazacyclooctane (L8, eight-membered ring), 1,4-diazacycloheptane (L7, seven-membered ring), or 1,4-diazacyclohexane (L6, six-membered ring) with a common 2-(2-pyridyl)ethyl side arm were synthesized and their reactivity toward O2 were compared. The copper(I) complex of L8 preferentially provided a mononuclear copper(II) end-on superoxide complex S as reported previously [Itoh, S., et al. J. Am. Chem. Soc. 2009, 131, 2788-2789], whereas a copper(I) complex of L7 gave a bis(μ-oxido)dicopper(III) complex O at a low temperature (-85 °C) in acetone. On the other hand, no such active-oxygen complex was detected in the oxygenation reaction of the copper(I) complex of L6 under the same conditions. In addition, O2-reactivity of the copper(I) complex supported by an acyclic version of the tridentate ligand (LA, PyCH2CH 2N(CH3)CH2CH2CH2N(CH 3)2; Py = 2-pyridyl) was examined to obtain a mixture of a (μ- η2:η2-peroxido)dicopper(II) complex SP and a bis(μ-oxido)dicopper(III) complex O. Careful inspection of the crystal structures of copper(I) and copper(II) complexes and the redox potentials of copper(I) complexes has revealed important geometric effects of the supporting ligands on controlling nuclearity of the generated copper active-oxygen complexes.
- Abe, Tsukasa,Morimoto, Yuma,Tano, Tetsuro,Mieda, Kaoru,Sugimoto, Hideki,Fujieda, Nobutaka,Ogura, Takashi,Itoh, Shinobu
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- Synthesis of Arylethylamines via C(sp3)-C(sp3) Palladium-Catalyzed Cross-Coupling
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Substituted arylethylamines represent a key structural motif in natural, pharmaceutical, and agrochemical compounds. Access to such scaffolds has been the subject of long-standing synthetic interest. Herein, we report the synthesis of such scaffolds via a palladium-catalyzed C(sp3)-C(sp3) coupling between (chloromethyl)aryls and air-/moisture-stable N,N-dialkylaminomethyltrifluoroborate salts. Rapid hit identification was achieved using microscale high-throughput experimentation and was followed by millimolar-scale reaction parameter optimization. A range of structurally and electronically varied arylethylamine products were obtained in moderate to excellent yields (27-96%, >60 examples). The reaction mechanism is proposed to proceed via formation of a trialkylbenzylammonium species prior to oxidative addition.
- Lippa, Rhys A.,Battersby, David J.,Murphy, John A.,Barrett, Tim N.
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p. 3583 - 3604
(2021/02/27)
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- Design, synthesis and in vitro activity of 1,4-disubstituted piperazines and piperidines as triple reuptake inhibitors
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Monoamine transporters regulate the concentration of monoamine neurotransmitters, which are essential for vital physiological processes, and their dysfunction can cause several central nervous system diseases. Monoamine transporters currently appear to be the potential target in the management of these disorders. In this study, homologation and bioisosterism techniques have been used in the designing of new 1,4-disubstituted piperazines and piperidines. These derivatives were synthesized and evaluated as potential triple reuptake inhibitors for studying the structure-activity relationships. The most advanced compound, 1-(4-(5-benzhydryl-1H-tetrazol-1-yl)butyl)-4-(3-phenylpropyl)piperazine (2i), was able to inhibit monoamine neurotransmitter reuptake in an in vitro test (IC50?=?158.7?nM for 5-HT, 99?nM for NE and 97.5?nM for DA). These novel potent triple reuptake inhibitor-based 1,4-disubstituted piperazine and piperidine scaffolds deserve further systematic optimization and pharmacological evaluation.
- Paudel, Suresh,Acharya, Srijan,Yoon, Goo,Kim, Kyeong-Man,Cheon, Seung Hoon
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p. 2266 - 2276
(2017/03/23)
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- TRICYCLIC COMPOUNDS
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Provided herein are compounds and pharmaceutical compositions comprising said compounds that are useful for treating cancers or congenital diseases. Specific cancers and congenital disease includes those that are mediated by YAP/TAZ.
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Paragraph 00273
(2017/08/01)
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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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- 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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- Biologically Active Compounds through Catalysis: Efficient Synthesis of N-(Heteroarylcarbonyl)-N′-(arylalkyl)piperazines
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A practical route for the synthesis of new biologically active 5-HT 2A receptor antagonists has been developed. In only three catalytic steps, this class of central nervous system (CNS) active compounds can be synthesized efficiently with high diversity. As the initial step, an anti-Markovnikov addition of amines to styrenes provides an easy route to N-(arylalkyl)piperazines, which constitute the core structure of the active molecules. Here, base-catalyzed hydroamination reactions of styrenes with benzylated piperazine proceeded in high yield even at room temperature. After catalytic debenzylation, the free amines were successfully carbonylated with different aromatic and heteroaromatic halides and carbon monoxide to yield the desired compounds in good to excellent yields. The two key reactions, base-catalyzed hydroamination of styrenes and palladium-catalyzed aminocarbonylation of haloarenes/heterocycles, showed tolerance towards various functional groups, thereby demonstrating the potential to synthesize a wide variety of new derivatives of this promising class of pharmaceuticals.
- Kumar, Kamal,Michalik, Dirk,Castro, Ivette Garcia,Tillack, Annegret,Zapf, Alexander,Arlt, Michael,Heinrich, Timo,Boettcher, Henning,Beller, Matthias
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p. 746 - 757
(2007/10/03)
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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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- Synthesis and class III type antiarrhythmic activity of 4-Aroyl (and Aryl)-1-aralkylpiperazines
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The synthesis and in vitro Class III antiarrhythmic activity of several 4-aroyl (and aryl)-1-aralkylpiperazine and piperidine derivatives are described. Among several potent compounds identified in the series, RWJ-28810 (3), with its EC20 of 3 nM, ranks as one of the most potent (in vitro) compounds reported. (C) 2000 Elsevier Science Ltd.
- Kanojia, Ramesh M.,Salata, Joseph J.,Kauffman, Jack
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p. 2819 - 2823
(2007/10/03)
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- Substituted pyrazoles as novel selective ligands for the human dopamine D4 receptor
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Two novel series of 3-(heterocyclylmethyl)pyrazoles have been synthesised and evaluated as ligands for the human dopamine D4 receptor. Compounds in series I (exemplified by 8k) have a phenyl ring joined to the 4-position of the pyrazole while those in series II (exemplified by 15j) have a 5-phenyl ring linked by a saturated chain to the 4-position of the pyrazole. Both series supplied compounds with excellent affinity for the human D4 and good selectivity over other dopamine receptors. Excellent selectivity over calcium, sodium, and potassium ion channels was also achieved. Copyright (C) 1997 Elsevier Science Ltd.
- Bourrain, Sylvie,Collins, Ian,Neduvelil, Joseph G.,Rowley, Michael,Leeson, Paul D.,Patel, Smita,Patel, Shil,Emms, Frances,Marwood, Rosemarie,Chapman, Kerry L.,Fletcher, Alan E.,Showell, Graham A.
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p. 1731 - 1743
(2007/10/03)
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