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81.
Anton V. Tverdokhlebov Elizaveta V. Resnyanska Andrey A. Tolmachev Alexander V. Zavada 《Monatshefte für Chemie / Chemical Monthly》2003,37(8):1045-1052
The title naphthyridines were found to be the sole products obtained after treatment of 2-amino-4-cyanomethyl-6-dialkylamino-3,5-pyridinedicarbonitriles
with alkoxides. The starting pyridine derivatives were prepared by amination of the readily available 2-amino-6-chloro-4-cyanomethyl-3,5-pyridinedicarbonitrile
in quantitative yields. 相似文献
82.
Elizaveta P. Shestakova Aleksei B. Nikolskii 《Journal of organometallic chemistry》2005,690(14):3397-3404
Cationic methyl complex of rhodium(III), cis-[Rh(Acac)(PPh3)2(CH3)(Py)][BPh4] (1) as a single isomer with Py in the trans to PPh3 position, is formed upon the reaction of cis-[Rh(Acac)(PPh3)2(CH3)(CH3CN)][BPh4] with pyridine in methylene chloride solution.Complex 1 was characterized by elemental analysis and by 31P{1H} and 1H NMR spectra.Cationic pentacoordinate acetyl complexes, trans-[Rh(Acac)(PPh3)2(COCH3)][BPh4] (2) and trans-[Rh(BA)(PPh3)2(COCH3)][BPh4] (3), are prepared by action of carbon monoxide on cis-[Rh(Acac)(PPh3)2(CH3)(CH3CN)][BPh4] and cis-[Rh(BA)(PPh3)2(CH3)(CH3CN)][BPh4], respectively, in methylene chloride solutions.Complexes 2 and 3 were characterized by elemental analysis and by IR, 31P{1H}, 13C{1H} and 1H NMR. According to NMR data, 2 and 3 in solution are non-fluxional trigonal bipyramids with β-diketonate and acetyl ligands in the equatorial plane and axial phosphines.In solutions, 2 and 3 gradually isomerize into octahedral methyl carbonyl complexes trans-[Rh(Acac)(PPh3)2(CO)(CH3)][BPh4] (4) and trans-[Rh(BA)(PPh3)2(CO)(CH3)][BPh4] (5), respectively.Complexes 4 and 5 were characterized by IR, 31P{1H}, 13C{1H} and 1H NMR, without isolation.Upon the action of PPh3 on cis-[Rh(Acac)(PPh3)2(CH3)(CH3CN)][BPh4] and cis-[Rh(BA)(PPh3)2(CH3)(CH3CN)] [BPh4], reductive elimination of the methyl ligand as a phosphonium salt, [CH3PPh3][BPh4], occurs to give square planar rhodium(I) complexes [Rh(Acac)(PPh3)2] and[Rh(BA)(PPh3)2], respectively. The reaction products were identified in the reaction mixtures by 31P{1H} and 1H NMR. 相似文献
83.
Rezeda A. Ishkaeva Ilyas S. Nizamov Dmitriy S. Blokhin Elizaveta A. Urakova Vladimir V. Klochkov Ilnar D. Nizamov Bulat I. Gareev Diana V. Salakhieva Timur I. Abdullin 《Molecules (Basel, Switzerland)》2021,26(10)
Phosphorus species are potent modulators of physicochemical and bioactive properties of peptide compounds. O,O-diorganyl dithiophoshoric acids (DTP) form bioactive salts with nitrogen-containing biomolecules; however, their potential as a peptide modifier is poorly known. We synthesized amphiphilic ammonium salts of O,O-dimenthyl DTP with glutathione, a vital tripeptide with antioxidant, protective and regulatory functions. DTP moiety imparted radical scavenging activity to oxidized glutathione (GSSG), modulated the activity of reduced glutathione (GSH) and profoundly improved adsorption and electrooxidation of both glutathione salts on graphene oxide modified electrode. According to NMR spectroscopy and GC–MS, the dithiophosphates persisted against immediate dissociation in an aqueous solution accompanied by hydrolysis of DTP moiety into phosphoric acid, menthol and hydrogen sulfide as well as in situ thiol-disulfide conversions in peptide moieties due to the oxidation of GSH and reduction of GSSG. The thiol content available in dissolved GSH dithiophosphate was more stable during air oxidation compared with free GSH. GSH and the dithiophosphates, unlike DTP, caused a thiol-dependent reduction of MTS tetrazolium salt. The results for the first time suggest O,O-dimenthyl DTP as a redox modifier for glutathione, which releases hydrogen sulfide and induces biorelevant redox conversions of thiol/disulfide groups. 相似文献
84.
Roman Ivanov Elizaveta Ivanova Vladislav Merkulov Dr. Mikhail Zharkov Dr. Ilya Kuchurov Prof. Sergei Zlotin 《European journal of organic chemistry》2023,26(25):e202300366
For the first time, condensations of amines with carbonyl compounds have been performed in supercritical carbon dioxide (sc-CO2). The reactions with aldehydes or active ketones proceed at moderate temperatures (35–55 °C) without use of external catalysts. The process is autocatalytic: it is accelerated by the carbonic acid generated in situ by interaction between the released water and the CO2 medium. The imine products were obtained in high yields in a crystalline form and did not require further purification. The one-pot transfer hydrogenation and [4+2] cycloaddition reactions performed in the CO2 medium have uncovered attractive prospects for facile green synthesis of more complex and valuable compounds from the generated in situ imine products. 相似文献
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87.
Erratum to: Small-Angle Neutron Scattering at the Pulsed Reactor IBR-2: Current Status and Prospects
Kuklin A. I. Ivankov O. I. Rogachev A. V. Soloviov D. V. Islamov A. Kh. Skoi V. V. Kovalev Yu. S. Vlasov A. V. Ryzhykau Yu. L. Soloviev A. G. Kucerka N. Gordeliy V. I. 《Crystallography Reports》2022,67(7):1304-1304
Crystallography Reports - An Erratum to this paper has been published: https://doi.org/10.1134/S1063774522070513 相似文献
88.
Thomas Doctor Olaf Witkowski Elizaveta Solomonova Bill Duane Michael Levin 《Entropy (Basel, Switzerland)》2022,24(5)
Intelligence is a central feature of human beings’ primary and interpersonal experience. Understanding how intelligence originated and scaled during evolution is a key challenge for modern biology. Some of the most important approaches to understanding intelligence are the ongoing efforts to build new intelligences in computer science (AI) and bioengineering. However, progress has been stymied by a lack of multidisciplinary consensus on what is central about intelligence regardless of the details of its material composition or origin (evolved vs. engineered). We show that Buddhist concepts offer a unique perspective and facilitate a consilience of biology, cognitive science, and computer science toward understanding intelligence in truly diverse embodiments. In coming decades, chimeric and bioengineering technologies will produce a wide variety of novel beings that look nothing like familiar natural life forms; how shall we gauge their moral responsibility and our own moral obligations toward them, without the familiar touchstones of standard evolved forms as comparison? Such decisions cannot be based on what the agent is made of or how much design vs. natural evolution was involved in their origin. We propose that the scope of our potential relationship with, and so also our moral duty toward, any being can be considered in the light of Care—a robust, practical, and dynamic lynchpin that formalizes the concepts of goal-directedness, stress, and the scaling of intelligence; it provides a rubric that, unlike other current concepts, is likely to not only survive but thrive in the coming advances of AI and bioengineering. We review relevant concepts in basal cognition and Buddhist thought, focusing on the size of an agent’s goal space (its cognitive light cone) as an invariant that tightly links intelligence and compassion. Implications range across interpersonal psychology, regenerative medicine, and machine learning. The Bodhisattva’s vow (“for the sake of all sentient life, I shall achieve awakening”) is a practical design principle for advancing intelligence in our novel creations and in ourselves. 相似文献
89.
Aleksandr G. Shipov Evgeniya P. Kramarova Elizaveta A. Mamaeva Oksana A. Zamyshlyaeva Vadim V. Negrebetsky Yuri E. Ovchinnikov Sergey A. Pogozhikh Alan R. Bassindale Peter G. Taylor Yuri I. Baukov 《Journal of organometallic chemistry》2001,620(1-2):139-149
Reactions of 2-sila-5-morpholinones, 4-acyl-2-silamorpholines and 4-acyl-2,6-disilamorpholines with electrophilic reagents generally lead to the opening of the sila- or disilacycle by cleavage of the Si–O bond with subsequent rearrangement to form five-membered chelate derivatives where the amide oxygen atoms coordinate with the silicon to form pentacoordinate silicon species. Multinuclear NMR spectroscopy and X-ray diffraction studies were used for structural investigation of the products. 4-Acyl-2,6-disilamorpholines initially form adducts with strong acids where the amide oxygen is protonated by the acid as demonstrated by X-ray crystallography. 相似文献
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