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Katarzyna Zielińska Katarzyna Szymańska Roman Mazurkiewicz Andrzej Jarzębski 《Tetrahedron: Asymmetry》2017,28(1):146-152
The kinetic resolution of racemic 1-(N-acylamino)alkylphosphonic acids 3 (R3 = OH) and their dimethyl esters 1, as well as 1-(N-acylamino)alkylphosphinic acids 4 (R3 = H or Ph) using penicillin G acylase (PGA) immobilized on three types of mesoporous silicas in both a batch slurry system and in a continuous-flow reactor was studied. The initial hydrolytic deacylation rates in the presence of those catalysts were measured and the relationships between the substrate structure and the enzyme efficiency are discussed. The stereospecific hydrolysis of the N-acyl group of both racemic N-acylated phosphorus analogues of amino acids and their esters catalyzed by the immobilized PGA proved to be a highly effective method for the kinetic resolution of all the investigated compounds, with the stereochemical preference of PGA for (R)-substrates. 相似文献
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Madhusudan Shit Souvik Mukherjee Suvendu Maity Sachinath Bera Prasanta Ghosh 《印度化学会志》2022,99(7):100518
A dioxidovanadium(V) complex of type [(LONOH?)(VO2)] (1) was isolated where LONOH2 is a tridentate ONO donor benzhydrazide ligand. 1 undergoes an oxo transfer reaction with triphenylphosphine in presence of 8-hydroxyquinoline (HQ) and affords a monooxidovanadium(V) complex of type [(LONO2?)(VO)(Q?)] (2). 1 and 2 were substantiated by elemental analyses, ESI-mass, IR, 1H NMR, 51V NMR and UV–vis spectra. The molecular geometries of 1 and 2 were authenticated by single crystal X?ray crystallography. UV–vis absorption spectra of 1 and 2 display bands respectively at 325 and 320 nm due to oxido → vanadium(V) charge transfer transitions. 1 exhibit an irreversible cathodic peak at ?0.44 V whereas 2 displays a reversible cathodic wave at ?0.60 V in cyclic voltammogram due to the VO3+/VO2+ redox couple. 相似文献
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Yuliya S. Vysochinskaya Anton A. Anisimov Sergey A. Milenin Alexander A. Korlyukov Fedor M. Dolgushin Elena G. Kononova Alexander S. Peregudov Mikhail I. Buzin Olga I. Shchegolikhina Aziz M. Muzafarov 《Mendeleev Communications》2018,28(4):418-420
New all-cis-tetra(p-tolyl)cyclotetrasiloxanetetraol and its derivatives with Si(CH = CH2)Me and Si(H)Me2 groups have been prepared and characterized by IR and NMR spectroscopy, GPC, mass spectrometry, TGA and DSC. Molecular and crystalline structures of the tetraol and its derivative with four Si(CH = CH2)Me groups have been determined by single-crystal X-ray diffraction. 相似文献
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Kosaku Tanaka Yusuke Honma Chihiro Yamaguchi Lina Aoki Minami Saito Momoko Suzuki Kazuhiro Arahata Kaoru Kinoshita Kiyotaka Koyama Kenichi Kobayashi Hiroshi Kogen 《Tetrahedron》2019,75(8):1085-1097
The relative and absolute configurations of L-755,807 were established through total synthesis. All four possible stereoisomers were prepared via a convergent synthetic strategy, including a novel diastereoselective Darzens reaction of an α-alkoxy aldehyde with di-tert-butyl bromomalonate, an E-selective Horner–Wadsworth–Emmons reaction, and late-stage coupling of the ring and side-chain segments. Additionally, biological evaluation of the synthesized compounds revealed their potent inhibitory activities (IC50?=?5–21?μM) against amyloid-β aggregation for the treatment of Alzheimer's disease. 相似文献
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