Search results for "pelkistys"
showing 10 items of 21 documents
Dioxomolybdenum(VI) complexes of hydrazone phenolate ligands -syntheses and activities in catalytic oxidation reactions
2021
The new cis-dioxomolybdenum(VI) complexes [MoO2(L2)(H2O)] (2) and [MoO2(L3) (H2O)] (3) containing the tridentate hydrazone-based ligands (H2L2 = N'-(3,5-di-tert-butyl-2-hydroxybenzylidene)-4-methylbenzohydrazide and H2L3 = N'-(2-hydroxybenzylidene)-2-(hydroxyimino)propanehydrazide) have been synthesised and characterized via IR, 1H and 13C NMR spectroscopy, mass spectrometry, and single crystal X-ray diffraction analysis. The catalytic activities of complexes 2 and 3, and the analogous known complex [MoO2(L1)(H2O)] (1) (H2L1 = N'-(2-hydroxybenzylidene)-4-methylbenzohydrazide) have been evaluated for various oxidation reactions, viz. oxygen atom transfer from dimethyl sulfoxide to triphenylp…
Molecular docking and oxidation kinetics of 3-phenyl coumarin derivatives by human CYP2A13
2021
CYP2A13 enzyme is expressed in human extrahepatic tissues, while CYP2A6 is a hepatic enzyme. Reactions catalysed by CYP2A13 activate tobacco-specific nitrosamines and some other toxic xenobiotics in lungs.To compare oxidation characteristics and substrate-enzyme active site interactions in CYP2A13 vs CYP2A6, we evaluated CYP2A13 mediated oxidation characteristics of 23 coumarin derivatives and modelled their interactions at the enzyme active site.CYP2A13 did not oxidise six coumarin derivatives to corresponding fluorescent 7-hydroxycoumarins. The Km-values of the other coumarins varied 0.85���97 ��M, Vmax-values of the oxidation reaction varied 0.25���60 min���1, and intrinsic clearance var…
Experimental and Theoretical Investigations of the Redox Behavior of the Heterodichalcogenido Ligands [(EPiPr2)(TePiPr2)N]− (E = S, Se): Cyclic Catio…
2008
The two-electron oxidation of the lithium salts of the heterodichalcogenidoimidodiphosphinate anions [(EPiPr2)(TePiPr2)N]− (1a, E = S; 1b, E = Se) with iodine yields cyclic cations [(EPiPr2)(TePiPr2)N]+ as their iodide salts [(SPiPr2)(TePiPr2)N]I (2a) and [(SePiPr2)(TePiPr2)N]I (2b). The five-membered rings in 2a and 2b both display an elongated E−Te bond as a consequence of an interaction between tellurium and the iodide anion. One-electron reduction of 2a and 2b with cobaltocene produces the neutral dimers (EPiPr2NPiPr2Te−)2 (3a, E = S; 3b, E = Se), which are connected exclusively through a Te−Te bond. Two-electron reduction of 2a and 2b with 2 equiv of cobaltocene regenerates the corresp…
Computational studies of chemical looping combustion materials and CO₂ activating surfaces
2016
DFT Prediction of Enhanced Reducibility of Monoclinic Zirconia upon Rhodium Deposition
2018
Oxides are an important class of materials and are widely used, for example, as supports in heterogeneous catalysis. In a number of industrial catalytic processes, oxide supports actively participate in chemical transformations by releasing lattice oxygen anions. While this is intuitively understood for reducible oxides, the reducibility of irreducible oxides may be modified via nanoengineering or upon inclusion of foreign species. Our calculations predict that the ability of irreducible monoclinic zirconia to release oxygen improves substantially upon deposition of rhodium. Through a comprehensive screening of Rh/ZrO2 with different size of the rhodium species, we find that a Rh adatom and…
Synthesis of Polycyclic Indolines utilizing a reduction/cyclization cascade reaction
2021
Subsequent reduction and dearomatizing cyclization reactions open up an entry into the synthesis of novel N-fused polycyclic indolines. The dearomatizing cyclization as key step of the sequence proceeds well with Cu(OTf)2 or TfOH as catalyst. At elevated temperature reduction of nitro-substituted precursors with iron under acidic conditions affords a broad variety of polycyclic indolines directly in a two-step cascade reaction in good to excellent yields. Using the developed protocol, the alkaloids Tryptanthrin and Phaitanthrin C have been prepared. peerReviewed
Ketonien stereoselektiivinen pelkistys entsyymeillä
2016
Työn kirjallisessa osassa käsitellään ketonien enantioselektiivistä pelkistystä entsyymeillä. Entsymaattiset reaktiot ovat kiinnostavia hyvän selektiivisyytensä ja ympäristöystävällisyytensä takia. Kaikki ketoneja pelkistävät entsyymit tarvitsevat toimintaansa nikotiiniamidikofaktoria NADH tai NADPH ja voivat yleensä katalysoida reaktioita sekä hapetus- että pelkistyssuuntaan. Kofaktoreita kierrätetään reaktioissa yleensä joko isopropanolia hapettamalla tai erillisellä entsyymillä, kuten glukoosidehydrogenaasilla. Substraatin liukoisuuden parantamiseksi ja konsentraation kasvattamiseksi reaktioissa kannattaa käyttää veden lisäksi jotain orgaanista liuotinta. Kokeellisessa osassa tutkittiin …
DFT Prediction of Enhanced Reducibility of Monoclinic Zirconia upon Rhodium Deposition.
2018
Oxides are an important class of materials and are widely used, for example, as supports in heterogeneous catalysis. In a number of industrial catalytic processes, oxide supports actively participate in chemical transformations by releasing lattice oxygen anions. While this is intuitively understood for reducible oxides, the reducibility of irreducible oxides may be modified via nanoengineering or upon inclusion of foreign species. Our calculations predict that the ability of irreducible monoclinic zirconia to release oxygen improves substantially upon deposition of rhodium. Through a comprehensive screening of Rh/ZrO2 with different size of the rhodium species, we find that a Rh adatom and…
Understanding selective reduction reactions with heterogeneous Pd and Pt : climbing out of the black box
2016
Stereocontrolled synthesis of fluorine-containing piperidine γ-amino acid derivatives
2019
An efficient synthetic approach for the construction of fluorine‐containing piperidine γ‐amino acid derivatives has been developed. The synthetic concept was based on oxidative ring opening of an unsaturated bicyclic γ‐lactam (Vince‐lactam) through its ring C=C bond, followed by double reductive amination of the diformyl intermediate performed with various fluoroalkylamines. The method has been extended towards the access of alkylated and perfluoroalkylated substances and for γ‐lactam derivatives. The transformations proceeded with stereocontrol: the configuration of the stereocenters in the products were predetermined by the configuration of the chiral centers of the starting γ‐lactam. The…