Xn:Harmful;
110-43-0Relevant articles and documents
Ruthenium NNN complexes with a 2-hydroxypyridylmethylene fragment for transfer hydrogenation of ketones
Shi, Jing,Shang, Shu,Hu, Bowen,Chen, Dafa
, (2018)
Four NNN tridentate ligands L1–L4 containing 2-methoxypyridylmethene or 2-hydroxypyridylmethene fragment were synthesized and introduced to ruthenium centers. When (HOC5H3NCH2C5H3NC5H7N2) (L2) and (HOC5H3NCH2C5H3NC6H6N3) (L4) reacted with RuCl2(PPh3)3, two ruthenium chloride products Ru(L2)(PPh3)Cl2 (1) and Ru(L4)(PPh3)Cl2 (2) were isolated, respectively. Reactions of (MeOC5H3NCH2C5H3NC5H7N2) (L1) and (MeOC5H3NCH2C5H3NC6H6N3) (L3) with RuCl2(PPh3)3 in the presence of NH4PF6 generated two dicationic complexes [Ru(L1)2][PF6]2 (3) and [Ru(L3)2][PF6]2 (4), respectively. Complex 1 reacted with CO to afford product [Ru(L2)(PPh3)(CO)Cl][Cl]. The catalytic activity for transfer hydrogenation of ketones was investigated. Complex 1 showed the highest activity, with a turnover frequency value of 1.44?×?103?h?1 for acetophenone, while complexes 3 and 4 were not active.
Deuteration enhances catalyst lifetime in palladium-catalysed alcohol oxidation
Armenise, Nicola,Tahiri, Nabil,Eisink, Niek N. H. M.,Denis, Mathieu,J?ger, Manuel,De Vries, Johannes G.,Witte, Martin D.,Minnaard, Adriaan J.
, p. 2189 - 2191 (2016)
The catalyst palladium/2,9-CD3-phenanthroline has a 1.8 times higher turnover number than its non-deuterated counterpart in the aerobic alcohol oxidation of methyl glucoside and allows the regioselective oxidation with dioxygen as the terminal oxidant.
Fungal mediated kinetic resolution of racemic acetates to (R)-alcohols using Fusarium proliferatum
Jadhav, Dipesh D.,Patil, Harshal S.,Chaya, Patil S.,Thulasiram, Hirekodathakallu V.
, p. 4563 - 4567 (2016)
Fungal mediated kinetic resolution of seven acyclic/aromatic acetates was achieved using Fusarium proliferatum to furnish (R)-alcohols in high enantiomeric excess (>95%). The kinetic resolution was established as one-pot two-step de-esterification/oxidation biocatalytic process. Further, the preparative scale synthesis of (R)-(+)-1-phenylethanol was accomplished through de-esterification/oxidation of (±)-1-phenylethyl acetate using the whole cell of F. proliferatum NCIM 1105.
REACTIVITE DES DERIVES ORGANOMANGANEUX-VIII; PREPARATION DE CETONES PAR ACYLATION D'ORGANOMANGANEUX. INFLUENCE DE LA NATURE DE L'AGENT ACYLANT, DES SOLVANTS ET DES LIGANDS
Friour, G.,Alexakis, A.,Cahiez, G.,Normant, J.
, p. 683 - 694 (1984)
The influence of the nature of acylating reagents, solvents and ligands on the preparation of ketones by acylation of organomanganous reagents is studied.Thus acid chlorides in ether, symmetrical acid anhydrides in ether or THF and mixed carboxylic-carbonic anhydrides (R'COOCOOEt) in ether are compared, they lead to the corresponding ketones with good or excellent yields.Some problems of reproductibility are encountered and discussed when mixed anhydrides R'COOCOOEt are used in THF.The addition of a great variety of cosolvents (e.g.C6H6, AcOEt, CO3Et2, CH3CN, CH2Cl2...) to the reaction mixture before addition of the acylating reagent does not affect the yield of ketones.In comparison the complexation of organomanganous reagents by several ligands (e.g.Me2S or Ph3P) has no subsequent effect on their acylation.The main limitation for the choice of solvents or ligands is the use of amino derivatives which generally lead to a very low yield of ketones (e.g.C5H5N, TMEDA, Et3N) or unreproducible yields (e.g.HMPA).Two applications of these studies are described: -The stabilization of s or t-alkyl manganous derivatives by complexation which leads to the best yield of the corresponding ketones -The use of a cosolvent in order to increase the yield when mixed anhydrides R'COOCOOEt are used in THF.
Copper(ii) complexes with 2,2′:6′,2′′-terpyridine, 2,6-di(thiazol-2-yl)pyridine and 2,6-di(pyrazin-2-yl)pyridine substituted with quinolines. Synthesis, structure, antiproliferative activity, and catalytic activity in the oxidation of alkanes and alcohols with peroxides
Choroba, Katarzyna,Machura, Barbara,Kula, Slawomir,Raposo, Luis R.,Fernandes, Alexandra R.,Kruszynski, Rafal,Erfurt, Karol,Shul'Pina, Lidia S.,Kozlov, Yuriy N.,Shul'Pin, Georgiy B.
, p. 12656 - 12673 (2019)
A series of 2,2′:6′,2′′-terpyridine (terpy), 2,6-di(thiazol-2-yl)pyridine (dtpy) and 2,6-di(pyrazin-2-yl)pyridine (dppy) derivatives with n-quinolyl substituents (n = 2 and 4) was used to synthesize five-coordinate complexes [CuCl2(n-quinolyl-terpy)] (1-2), [CuCl2(n-quinolyl-dtpy)] (3-4) and [CuCl2(n-quinolyl-dppy)] (5-6), respectively. The main emphasis of the research was to investigate the impact of the triimine skeleton (terpy, dtpy and dppy) and n-quinolyl pendant substituent on the antiproliferative and catalytic properties of 1-6. The obtained Cu(ii) compounds were studied as antiproliferative agents against human colorectal (HCT116) and ovarian (A2780) carcinoma, and they were used as catalysts for the oxidation of alkanes and alcohols with peroxides under mild conditions. The kinetic characteristics of the oxidizing species generated by the catalytic system Cu(ii) complex-H2O2 in CH3CN were obtained from the dependence of the alkane oxidation rate on its initial concentration. A model of competitive interaction of hydroxyl radicals with CH3CN and RH in the catalyst cavity has been proposed which is based on the simultaneous study of kinetics and selectivity in alkane oxidations.
Oxidation of Higher Alcanols by Tetra-1-butylammonium Permanganate
Holba, V.,Sumichrast, R.
, p. 681 - 686 (1995)
Oxidations of hexan-1-ol, hexan-2-ol, hexan-3-ol, heptan-1-ol, heptan-2-ol, octan-1-ol, and octan-2-ol with tetra-1-butylammonium permanganate, dissolved in the same alcohols, proceed partly autocatalytically.The rate constants of both catalytic and non-catalytic reactions have been evaluated.Colloidal manganese dioxide, one of the reaction products, has been identified as the catalyst. - Keywords: Autocatalysis; Kinetic parameters; Colloidal MnO2
Selective oxidation of activated alcohols by the combination of H 2O2, AcOH and NaBr: An efficient metal-free alternative
Qi, Xingyi,Wang, Jing,Zheng, Liwei,Qi, Lin
, p. 555 - 558 (2011)
The ternary HAcOH-NaBr combination has been found to be extremely effective for the oxidation of benzyl alcohol and its derivatives. Comparative studies indicated that the addition of NaBr offered significant improvement in product yields and selectivity towards aldehyde formation. Georg Thieme Verlag Stuttgart New York.
Diazo chemistry controlling the selectivity of olefin ketonisation by nitrous oxide
Hermans, Ive,Moens, Bart,Peeters, Jozef,Jacobs, Pierre,Sels, Bert
, p. 4269 - 4274 (2007)
The thermal reaction of olefins with nitrous oxide was recently put forward as a promising synthetic ketone source. The 1,3-dipolar cycloaddition of N 2O to the C=C double bond, forming a 4,5-dihydro-[1,2,3]oxadiazole intermediate, was predicted to be the first elementary reaction step. This oxadiazole can subsequently decompose to the desired carbonyl product and N 2 via a hydrogen shift. In this contribution, Potential Energy Surfaces are constructed at the reliable G2M level of theory and used to evaluate thermal rate constants by Transition State Theory. Compelling theoretical and experimental evidence is presented that an oxadiazole intermediate not only can undergo a hydrogen shift, but eventually also a methyl- or even an alkyl-shift. Special emphasis is also given on a hitherto neglected decomposition of the oxadiazole via a concerted C-C and N-O cleavage. For some substrates, such as internal olefins, this diazo route is negligibly slow, compared to the ketone path, leaving no marks on the selectivity. For cyclopentene the diazo cleavage was however found to be nearly as fast as the desired ketone route. However, the diazo compound, viz. 5-diazopentanal, reconstitutes the oxadiazole much faster upon ring-closure than it is converted to side-products. Therefore, a pre-equilibrium between the diazoalkanal and the oxadiazole is established, explaining the high ketone yield. On the other hand, for primary alkenes, such a concerted C-C and N-O cleavage to diazomethane is identified as an important side reaction, producing aldehydes with the loss of one C-atom. For these substrates, the bimolecular back-reaction of the C n-1 aldehyde and diazomethane is too slow to sustain an equilibrium with the oxadiazole; diazomethane rather reacts with the substrate to form cyclopropane derivatives. The overall selectivity is thus determined by a combination of H-, methyl- or alkyl-shift, and the eventual impact of a diazo cleavage in the oxadiazole intermediate. the Owner Societies.
Direct Synthesis of Sulfines by Oxidation of Enethiolizable Thioketones
Nocher, Anne Marie Le,Metzner, Patrick
, p. 747 - 750 (1991)
Reaction of enethiolizable thioketones 2 with one equivalent of meta-chloroperoxybenzoic acid affords quantitatively the corresponding E sulfines 1.In contrast to literature expectations, direct synthesis of aliphatic sulfines by oxidation of thiocarbonyl compounds is thus possible; no divinyl disulfide 4 has been formed.
Layer-assembled 3D Bi2WO6 hierarchical architectures by Ti-doping for enhanced visible-light driven photocatalytic and photoelectrochemical performance
Arif, Muhammad,Zhang, Min,Yao, Jiacheng,Yin, Hongfei,Li, Pengfei,Hussain, Ijaz,Liu, Xiaoheng
, p. 878 - 893 (2019)
Layer-assembled three-dimensional (3D) catalysis gain substantial attention and widespread application in the field of photocatalysis and solar energy conversion. The 3D hierarchical architecture possesses large surface area and plenty reactive sites which contribute highly in catalysis performance. In this work we report a tetrabutyl titanate (TBT) assisted simultaneous approach of layer-assembled single-unit-cell 3D Bi2WO6 hierarchical architecture by Ti-doping. The Ti-doping beside its morphological effect can also generate crystal defects in the crystal lattice of Bi2WO6, resulting in highly enhanced visible-light driven photocatalytic performance towards highly stable refractory pollutants and profound photoelectrochemical ability. Moreover, the crystal defects mediated by Ti-doping can generate abundant oxygen vacancies which remarkably improve the selective adsorption towards different charges pollutants. Furthermore, the Ti-doping beside its great influence on the electron dynamic and band structure can also introduce the redox couples (Ti3+/Ti4+), resulting in significance enhancement in reactive oxygen species during photocatalytic reaction. The present work provides a valid route for constructing simultaneous approach of layer-assembled 3D hierarchical architecture and Ti-substitution in the crystal structure of Bi2WO6 with great improvement in photocatalytic and photoelectrochemical performance.
