1489-69-6Relevant articles and documents
Microstructured Au/Ni-fiber catalyst: Galvanic reaction preparation and catalytic performance for low-temperature gas-phase alcohol oxidation
Zhao, Guofeng,Deng, Miaomiao,Jiang, Yifeng,Hu, Huanyun,Huang, Jun,Lu, Yong
, p. 46 - 53 (2013)
The highly active and selective gold catalysts were successfully prepared by galvanically depositing Au onto a thin-sheet microfibrous structure consisting of 5 vol.% 8-μm Ni-fiber and 95 vol.% voidage, with high heat conductivity and good stability for the gas-phase oxidation of alcohols. The best catalyst was Au-4/Ni-fiber-300 (Au-loading: 4 wt%; calcined at 300 °C in air), being effective for oxidizing acyclic, benzylic, and polynary (1,2-propanediol) alcohols. For benzyl alcohol, the conversion of 95% was achieved with 99% selectivity to benzaldehyde within 660 h test at 250 °C, while a low ΔT of 2 formed at Au galvanic deposition step into NiO was identified along with the low-temperature activity promotion. This suggests a special synergistic effect between NiO and Au particles, of which comprehensive understanding is particularly desirable.
Practical Os/Cu-cocatalyzed air oxidation of allyl and benzyl alcohols at room temperature and atmospheric pressure
Muldoon, John,Brown, Seth N.
, p. 1043 - 1045 (2002)
(equation presented) A new protocol for the oxidation of primary and secondary allyl and benzyl alcohols at room temperature and using 1 atm of air is described. The procedure uses low loadings of copper salts and osmium tetroxide, which is activated with quinuclidine and prereduced with an alkene. Chemoselectivity for allyl and benzyl alcohols is very high, no overoxidation is observed, and the reaction takes place under neutral conditions.
Cyclopropanation of Electron-deficient Olefins with Dibromomethane by Ni(0) Complexes and Zinc
Kanai, Hiroyoshi,Hiraki, Nobuyuki,Iida, Shigeki
, p. 1025 - 1029 (1983)
A new method for the synthesis of cyclopropane derivatives is described. It involves treatment of electron-deficient olefins with dibromomethane in the presence of Ni(0) complex/zinc/Lewis acid (or alkali halide) systems. Ni(PPh3)4/Zn/ZnBr2 system was effective for the cyclopropanation of methyl acrylate and acrylonitrile, but was ineffective for that of methyl vinyl ketone and acrylaldehyde. Ni(COD)2/Zn/NaI system was applicable to the cyclopropanation of methyl vinyl ketone as well as to that of methyl acrylate and acrylonitrile. Alternative catalytic systems which were easy to handle were exploited, involving in situ generated Ni(0) complexes prepared from NiBr2(PPh3)2 and zinc, or nickel bromide, sodium iodide, zinc, and an olefin. Catalytic amounts of nickel compounds are sufficient for the cyclopropanation of methyl acrylate, acrylonitrile, and methyl vinyl ketone, but a 1:2 nickel:acrylaldehyde mole ratio results in the best yield. A mechanism is proposed which involves metallacyclobutane as an intermediate.
Scope, Limitation, and Mechanism of the Homoconjugate Electrophilic Addition of Hydrogen Halides
Lambert, Joseph B.,Napoli, James J.,Johnson, Katharine Kappauf,Taba, Kalulu N.,Packard, Beverly Sue
, p. 1291 - 1295 (1985)
Hydrogen halides (HCl, HBr, HI) add by a homoconjugate 1,5 mechanism to cyclopropanes carrying certain electron-withdrawing substituents.When the substituent is COCH3, COC6H5, CO2H, or CN, the reaction gives the 1,3-disubstituted propane in high yield.Addition of DCl gives a product with deuterium only in the position α to the substituent.The order of rates is not in agreement with a mechanism whereby the cyclopropane ring is protonated initially, since the rate of such a process should be slowed by electron-withdrawing groups.The ketones, however, react much more rapidly than benzylcyclopropane, a model for the direct protonation mechanism.The homoconjugate mechanism involves rapid protonation of the side chain, followed by nucleophilic attack on the cyclopropane ring.The reaction is limited to substrates that can be protonated on the side chain to produce an intermediate with charge ajacent to the cyclopropane ring.This charge must be able to be transmitted by resonance to the unsubstituted ring positions in order to facilitate the nucleophilic step.
Cu3Pt1-Cu2O nanocomposites: Synergistic effect-dependent high activity and stability for the gas-phase selective oxidation of alcohols
Liu, Kun,Long, Houkun,Wang, Guangyi,Sun, Yongbin,Hou, Chao,Dong, Jian,Cao, Xiaoqun
, p. 54861 - 54865 (2017)
The catalyst Cu3Pt1-Cu2O/SiC was facilely prepared via the in situ reaction of the corresponding compounds supported on SiC in the reaction stream. Cu3Pt1-Cu2O/SiC exhibits excellent catalytic activity for the oxidation of alcohols (conversion of benzyl alcohol and selectivity of benzyl aldehyde are 93% and 98% respectively). The reduction of active Cu2O to inactive Cu0 is the cause behind the deactivation of Cu/SiC. For Cu3Pt1-Cu2O-7/SiC, a Cu2O-Cu3Pt1 alloy formed under the reaction conditions plays an important role in the reaction. Active 5 nm Cu2O nanoparticles are stabilized by the inactive Cu3Pt1 alloy, which was confirmed by control experiments, characterization results and a three-step experiment.
ELECTROCHEMICAL AND CHEMICAL OXIDATION OF ALCOHOLS IN A TWO-PHASE SYSTEM USING N-OXOPIPERIDINUM SALT: SYNTHESIS OF 4-CHLOROBUTANAL, FORMYLCYCLOPROPANES, AND m-PHENOXYBENZALDEHYDE
Ogibin, Yu. N.,Khusid, A. Kh.,Nikishin, G. I.
, p. 735 - 739 (1992)
Oxidation of 4-chlorobutanol-1, cyclopropylcarbinols, and m-phenoxybenzyl alcohol with electrogenerated bromine, molecular bromine, and sodium hypochlorite using N-oxopiperidinium salt in the two-phase system CH2Cl2-water gave the corresponding carbonyl compounds with good yields.Keywords: indirect electrooxidation, 4-chlorobutanol-1, cyclopropylcarbinols, m-phenoxybenzyl alcohol, 2,2,6,6-tetramethyl-4-benzoyloxypiperidine-1-oxide, bromine, sodium hypochloriate, 4-chlorobutanal, formylcyclopropanes, m-phenoxybenzaldehyde.
Short-lived 1,5-biradicals formed from triplet 1-alkoxy- and 1-(benzyloxy)-9,10-anthraquinones
Smart, Robert P.,Peelen, Timothy J.,Blankespoor, Ronald L.,Ward, Donald L.
, p. 461 - 465 (1997)
The cyclopropylmethyl and (trans-2-phenylcyclopropyl)methyl radical clocks were used to estimate the lifetimes of triplet state biradicals formed from substituted 1-alkoxy-9,10-anthraquinones by photoexcitation and subsequent 1,5-hydrogen atom transfer. Irradiation (350 nm) of 1-(cyclopropylmethoxy)-2-methyl-9,10-anthraquinone (1cp) in argon-purged methanol generated the primary anthrahydroquinone product (2). Upon exposure to air, 2 was rapidly converted to cyclopropanecarboxaldehyde and 1-hydroxy-2-X-9,10-anthraquinone (3). In contrast, irradiation of 1-{(trans-2-phenylcyclopropyl)methoxy}-2-benzyl-9,10-anthraquinone (1pcp) under similar conditions produced only small amounts of 3 and the corresponding aldehyde, trans-(2-phenylcyclopropyl)carboxaldehyde. In addition, products resulting from rearrangement of the 1,5-biradical to a homoallylic 1,8-biradical were also obtained. Using the known rate constant for the rearrangement of the phenylcyclopropylmethyl radical to the homoallylic radical and the observed product ratio, lifetimes of approximately 1-2 ns were estimated for 1,5-biradicals from these anthraquinones which are about an order of magnitude shorter than those reported for triplet state biradicals derived from structurally related benzophenones and acetophenones. The short lifetimes of these biradicals are attributed to the facile formation of a zwitterion which results from an intramolecular electron transfer from one radical site, which serves as electron donor, to the other radical site, which is a semianthraquinone and therefore serves as a good electron acceptor. If either the electron-donating or electron-accepting site is absent in the biradical, zwitterion formation is not observed and coupling of the biradical occurs resulting in a longer lifetime.
Oxetane ring enlargement through nucleophilic trapping of radical cations by acetonitrile
Perez-Ruiz, Raul,Saez, Jose A.,Domingo, Luis R.,Jimenez, M. Consuelo,Miranda, Miguel A.
, p. 5700 - 5703 (2012)
Oxidative electron transfer cycloreversion of trans,trans-2-cyclopropyl-4- methyl-3-phenyloxetane, using triphenylthiapyrylium perchlorate as a photosensitizer, leads to distonic 1,4-radical cations; subsequent cleavage gives rise to fragmentation products (pathway a), whereas nucleophilic trapping by acetonitrile affords a ring expanded oxazine (pathway b).
Kinetics of Cyclopentene Isomerization at 1200 K
Lewis, David K.,Baldwin, John E.,Cianciosi, Steven J.
, p. 7464 - 7467 (1990)
This study was conducted to determine the rate of intramolecular degenerate rearrangement of cyclopentene (CP), presumably via reversible conversion to vinylcyclopropane (VCP).Cyclopentene-3-13C was synthesized and heated to 1200 K in a single-pulse shock tube and then analyzed by 13C NMR to ascertain the extent of migration of the 13C label to the 4-position.The very small amounts of migration observed were consistent with log k (CP -> VCP) = 15.7 - (16000/T).This rate constant for CP -> VCP is too small to account for the previously reported evidence of multiple channels for H2 elimination from CP.
Method for synthesizing cyclopropanecarboxaldehyde from 1,4-butanediol
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Paragraph 0054-0058; 0064-0068, (2021/03/13)
The invention relates to a method for synthesizing cyclopropanecarboxaldehyde from 1,4-butanediol. The method has the advantages of accessible raw materials, low cost and simple technique, can implement one-step reaction, has high efficiency, and can implement continuous operation.
