- 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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- One-Pot Synthesis of Indoles and Pyrazoles via Pd-Catalyzed Couplings/Cyclizations Enabled by Aqueous Micellar Catalysis
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An effective one-pot synthesis of either indoles or pyrazoles can be achieved via Pd-catalyzed aminations followed by subsequent cyclizations facilitated by aqueous micellar catalysis. This new technology includes efficient couplings with low loadings of palladium, a more stable source of the required hydrazine moiety, greater atom economy for the initial coupling, and reduced reaction temperatures, all leading to environmentally responsible processes.
- Akporji, Nnamdi,Braga, Felipe C.,Gabriel, Christopher M.,Landstrom, Evan B.,Lee, Nicholas R.,Lipshutz, Bruce H.
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supporting information
(2020/09/02)
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- Azologization of serotonin 5-HT3 receptor antagonists
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The serotonin 5-hydroxytryptamine 3 receptor (5-HT3R) plays a unique role within the seven classes of the serotonin receptor family, as it represents the only ionotropic receptor, while the other six members are G protein-coupled receptors (GPCRs). The 5-HT3 receptor is related to chemo-/radiotherapy provoked emesis and dysfunction leads to neurodevelopmental disorders and psychopathologies. Since the development of the first serotonin receptor antagonist in the early 1990s, the range of highly selective and potent drugs expanded based on various chemical structures. Nevertheless, on-off-targeting of a pharmacophore’s activity with high spatiotemporal resolution as provided by photopharmacology remains an unsolved challenge bearing additionally the opportunity for detailed receptor examination. In the presented work, we summarize the synthesis, photochromic properties and in vitro characterization of azobenzene-based photochromic derivatives of published 5-HT3R antagonists. Despite reported proof of principle of direct azologization, only one of the investigated derivatives showed antagonistic activity lacking isomer specificity.
- Rustler, Karin,Maleeva, Galyna,Bregestovski, Piotr,K?nig, Burkhard
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p. 780 - 788
(2019/04/17)
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- SUBSTITUTED SULFONYL HYDRAZIDES AS INHIBITORS OF LYSINE BIOSYNTHESIS VIA THE DIAMINOPIMELATE PATHWAY
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The present invention relates to substituted sulfonyl hydrazides that have the ability to inhibit lysine biosynthesis via the diaminopimelate pathway in certain organisms. As a result of this activity these compounds can be used in applications where inhibition of lysine biosynthesis is useful applications of this type include the use of the compound as herbicides and/or anti- bacterial agents.
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Paragraph 0219
(2020/01/24)
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- Gold(I)-catalyzed rearrangement of alkynylaziridine indoles for the synthesis of spiro-tetrahydro-β-carbolines
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Functionalized spiro-tetrahydro-β-carbolines were formed by an efficient gold(I)-catalyzed rearrangement reaction of alkynylaziridine indoles. The reaction involved a Friedel-Crafts type intramolecular reaction of alkynylaziridine indoles, following by hydroamination of aminoallene intermediate.
- Yang, Yan-Fang,Li, Lian-Hua,He, Yu-Tao,Luo, Jian-Yi,Liang, Yong-Min
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p. 702 - 707
(2014/02/14)
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- Use of phenyl hydrazines for seed biostimulation or the treatment of lipoxygenase mediated seed deteriorations
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The present invention provides a method of treating certain deleterious conditions mediated by the action of lipoxygenases in mammals and seeds using certain phenyl hydrazines. Also provided is a method for seed biostimulation using these phenyl hydrazines.
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- Process for producing 3-anilino-5-pyrazolones
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A process for producing a 3-anilino-5-pyrazolone which comprises reacting a β-anilino-β-alkoxy-acrylate with a hydrazine in the presence of a compound having a pKa of about 8 up to about 14.
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