- Cross-Coupling between Hydrazine and Aryl Halides with Hydroxide Base at Low Loadings of Palladium by Rate-Determining Deprotonation of Bound Hydrazine
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Reported here is the Pd-catalyzed C–N coupling of hydrazine with (hetero)aryl chlorides and bromides to form aryl hydrazines with catalyst loadings as low as 100 ppm of Pd and KOH as base. Mechanistic studies revealed two catalyst resting states: an arylpalladium(II) hydroxide and arylpalladium(II) chloride. These compounds are present in two interconnected catalytic cycles and react with hydrazine and base or hydrazine alone to give the product. The selectivity of the hydroxide complex with hydrazine to form aryl over diaryl hydrazine was lower than that of the chloride complex, as well as the catalytic reaction. In contrast, the selectivity of the chloride complex closely matched that of the catalytic reaction, indicating that the aryl hydrazine is derived from this complex. Kinetic studies showed that the coupling process occurs by rate-limiting deprotonation of a hydrazine-bound arylpalladium(II) chloride complex to give an arylpalladium(II) hydrazido complex.
- Borate, Kailaskumar,Choi, Kyoungmin,Goetz, Roland,Hartwig, John F.,Shinde, Harish,Wang, Justin Y.,Zuend, Stephan J.
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supporting information
p. 399 - 408
(2020/10/29)
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- A novel potent metal-binding NDM-1 inhibitor was identified by fragment virtual, SPR and NMR screening
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NDM-1 can hydrolyze nearly all available β-lactam antibiotics, including carbapenems. NDM-1 producing bacterial strains are worldwide threats. It is still very challenging to find a potent NDM-1 inhibitor for clinical use. In our study, we used a metal-binding pharmacophore (MBP) enriched virtual fragment library to screen NDM-1 hits. SPR screening helped to verify the MBP virtual hits and identified a new NDM-1 binder and weak inhibitor A1. A solution NMR study of 15N-labeled NDM-1 showed that A1 disturbed all three residues coordinating the second zinc ion (Zn2) in the active pocket of NDM-1. The perturbation only happened in the presence of zinc ion, indicating that A1 bound to Zn2. Based on the scaffold of A1, we designed and synthesized a series of NDM-1 inhibitors. Several compounds showed synergistic antibacterial activity with meropenem against NDM-1 producing K. pneumoniae.
- Bai, Weiqi,Cheng, Kai,Gao, Yan,Guo, Huifang,He, Wei,Li, Conggang,Li, Zhuorong,Wu, Cai
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- PROCESS FOR THE SYNTHESIS OF ARYL HYDRAZINES
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The invention relates to a process for the synthesis of aryl hydrazinesof formula I or a salt thereof, which process comprises subjecting an arene of formula II to a coupling reaction with hydrazine or a derivative thereof, wherein the coupling reaction is conducted in the presence of a catalyst comprising palladium and a diphosphine ligand, wherein the phosphorus atoms are connected through two, three, four, or five atoms selected from car- bon, nitrogen, oxygen or iron, and in which the non-connecting phosphorus substituents are C1- C 10-alkyl or C3-C10-cycloalkyl, wherein the amount of Pd used is up to 0.5 mol-% relative to the amount of arene of formula II; and a base.
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Page/Page column 22; 24
(2020/06/01)
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- Diversification of edaravone via palladium-catalyzed hydrazine cross-coupling: Applications against protein misfolding and oligomerization of beta-amyloid
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N-Aryl derivatives of edaravone were identified as potentially effective small molecule inhibitors of tau and beta-amyloid aggregation in the context of developing disease-modifying therapeutics for Alzheimer's disease (AD). Palladium-catalyzed hydrazine monoarylation protocols were then employed as an expedient means of preparing a focused library of 21 edaravone derivatives featuring varied N-aryl substitution, thereby enabling structure-activity relationship (SAR) studies. On the basis of data obtained from two functional biochemical assays examining the effect of edaravone derivatives on both fibril and oligomer formation, it was determined that derivatives featuring an N-biaryl motif were four-fold more potent than edaravone.
- Maclean, Mark A.,Diez-Cecilia, Elena,Lavery, Christopher B.,Reed, Mark A.,Wang, Yanfei,Weaver, Donald F.,Stradiotto, Mark
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supporting information
p. 100 - 104
(2015/12/18)
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- Efficient synthesis of aryl hydrazines using copper-catalyzed cross-coupling of aryl halides with hydrazine in PEG-400
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An efficient and convenient method for the synthesis of aryl hydrazines is described via copper-catalyzed cross-coupling of aryl halides with aqueous hydrazine in PEG-400. This protocol is applicable to both electron-deficient and electron-rich aryl iodides and bromides, and even to sterically hindered substrates, giving aryl hydrazines in good to excellent yields.
- Chen, Junmin,Zhang, Yimin,Hao, Wenyan,Zhang, Rongli,Yi, Fei
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p. 613 - 617
(2013/07/25)
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- Mild and rapid Pd-catalyzed cross-coupling with hydrazine in continuous flow: Application to the synthesis of functionalized heterocycles
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Minimizing risk: The synthesis of arylhydrazines through C?￡?N cross-coupling of aryl chlorides with hydrazine is described. Through the use of continuous flow, the hazards associated with the use of hydrazine in the presence of transition metals are decreased. In addition, multistep flow sequences have also been developed for the generation of functionalized heterocycles utilizing the arylhydrazine intermediates.
- Deangelis, Andrew,Wang, Dong-Hui,Buchwald, Stephen L.
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supporting information
p. 3434 - 3437
(2013/05/09)
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- 1, 5-DIHYDRO-PYRAZOLO (3, 4-D) PYRIMIDIN-4-ONE DERIVATIVES AND THEIR USE AS PDE9A MODULATORS FOR THE TEATMENT OF CNS DISORDERS
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The invention relates to novel substituted pyrazolopyrimidines. Chemically, the compounds are characterised by general Formula (I): with R1 being phenyl or pyridyl, any of which is substituted with 1 to 4, preferably 1 to 3 substituents X; X in
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Page/Page column 58
(2009/07/03)
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- SELECTIVE AZOLE PDE10A INHIBITOR COMPOUNDS
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The invention pertains to heteroaromatic compounds of the formula I, as defined herein, that serve as effective phosphodiesterase (PDE) inhibitors. In particular, the invention relates to said compounds which are selective inhibitors of PDE10. The invention also relates to pharmaceutical compositions comprising said compounds; and the use of said compounds in a method for treating certain central nervous system (CNS) or other disorders.
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Page/Page column 188
(2010/11/29)
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- PYRAZOLE DERIVATIVES
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A compound represented by formula (I): (wherein Ar1 represents a phenyl group which may have 1 to 3 substituents, or a non-substituted 5- or 6-membered aromatic heterocyclic group; Ar2 represents (i) a non-substituted phenyl group, (ii) a phenyl group which has been substituted by a lower alkyl group having 1 to 3 groups or atoms selected from among a carbamoyl group, an amino group, a hydroxyl group, a lower alkoxy group, and a halogen atom, or (iii) a 5- or 6-membered nitrogen-containing aromatic heterocyclic group which has been substituted by 1 to 3 groups or atoms selected from among a lower alkyl group, a lower alkynyl group, a lower alkanoyl group, a carbamoyl group, a cyano group, an amino group, a hydroxyl group, a lower alkoxy group, and a halogen atom; and X represents a group represented by formula (II): (wherein the ring structure represents a 4- to 7-membered heterocyclic group which may have, in addition to the nitrogen atom shown in formula (II), one heteroatom selected from among nitrogen, oxygen, and sulfur, and which may be substituted by 1 to 4 groups or atoms selected from among a lower alkyl group, a carbamoyl group, an amino group, a hydroxyl group, a lower alkoxy group, an oxo group, a lower alkanoyl group, a lower alkylsulfonyl group, and a halogen atom)), a salt thereof, a solvate of the compound or the salt, and a drug.
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Page/Page column 22
(2010/11/26)
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- AMIDOPYRAZOLE DERIVATIVE
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A platelet coagulation inhibitor which inhibits neither COX-1 nor COX-2 is provided. The inhibitor is a compound represented by general formula (I): wherein Ar1 and Ar2 independently represent a 5- or 6-membered aromatic heterocyclic group optionally substituted with 1 to 3 substituents, or a phenyl group optionally substituted with 1 to 3 substituents; R1 represents a lower acyl group, carboxyl group, a lower alkoxycarbonyl group, a lower alkoxy group, a lower alkyl group optionally substituted with 1 or 2 substituents, a carbamoyl group optionally substituted with 1 or 2 substituents, an oxamoyl group optionally substituted with 1 or 2 substituents, an amino group optionally substituted with 1 or 2 substituents, a 4- to 7-membered alicyclic heterocyclic group optionally substituted with 1 or 2 substituents, a phenyl group optionally substituted with 1 to 3 substituents, or a 5- or 6-membered aromatic heterocyclic group optionally substituted with 1 to 3 substituents; and R2 represents hydrogen atom, a halogeno group, or the like.
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Page/Page column 35-36; 47
(2010/11/23)
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- THIAZOLIDINE DERIVATIVE AND MEDICINAL USE THEREOF
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A thiazolidine derivative represented by the formula (I) wherein each symbol is as defined in the specification, and a pharmaceutically acceptable salt thereof exhibit a potent DPP-IV inhibitory activity, and can be provided as an agent for the prophylaxis or treatment of diabetes, an agent for the prophylaxis or treatment of obesity and the like.
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- 2-(pyrazol-5-yl-oxymethyl)-1,2-benzisothiazol-3 (2H)-One 1, 1-dioxides and compositions and method of use thereof
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2-(Pyrazol-5-yl-oxymethyl)-1,2-benzisothiazol-3(2H)-one 1,1-dioxides, pharmaceutical compositions containing them and methods for the treatment of degenerative diseases utilizing them.
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