142-82-5Relevant articles and documents
Zweifel,Steele
, p. 6021,6023 (1966)
Platinum Hydroformylation Catalysts containing Diphenylphosphine Oxide Ligands
Leeuwen, Piet W. N. M. van,Roobeek, Cornelis F.,Wife, Richard L.,Frijns, John H. G.
, p. 31 - 33 (1986)
Platinum complexes of the general formula Pt(H)(Ph2PO)(Ph2POH)(PPh3) (1a) catalyse the hydroformylation of hept-1-ene and, more significantly, hept-2-ene, yielding products of high linearity (90 and 60percent, respectively); the intermediate alkyl and acyl complexes (1c-e) which most often escape direct observation in a catalytic system, have been successfully isolated and identified.
REACTION OF HCo(CO)4 WITH OLEFINS, EFFECT OF Co2(CO)8
Ungvary, Ferenc,Marko, Laszlo
, p. 397 - 400 (1981)
Dicobalt octacarbonyl catalyzes the formation of acylcobalt tetracarbonyls and paraffins from olefins and cobalt tetracarbonyl hydride, presumably by generating radical species.The relative reactivities of CO and HCo(CO)4 towards an alkylcobalt carbonyl determine the carbonylation/hydrogenation ratio.
The effect of TiO2 particle size on the characteristics of Au-Pd/TiO2 catalysts
Kittisakmontree, Prathan,Yoshida, Hiroshi,Fujita, Shin-Ichiro,Arai, Masahiko,Panpranot, Joongjai
, p. 70 - 75 (2015)
The nanocrystalline TiO2 materials with average crystallite sizes of 9 and 15 nm were synthesized by the solvothermal method and employed as the supports for preparation of bimetallic Au/Pd/TiO2 catalysts. The average size of Au-Pd alloy particles increased slightly from sub-nano (2 crystallite size from 9 to 15 nm. The catalyst performances were evaluated in the liquid-phase selective hydrogenation of 1-heptyne under mild reaction conditions (H2 1 bar, 30 °C). The exertion of electronic modification of Pd by Au-Pd alloy formation depended on the TiO2 crystallite size in which it was more pronounced for Au/Pd on the larger TiO2 (15 nm) than on the smaller one (9 nm), resulting in higher hydrogenation activity and lower selectivity to 1-heptene on the former catalyst.
HYDROGENATION OF ALKENES AND ALKYNES ON Pd-POLYHETEROARYLENE CATALYSTS TREATED WITH SODIUM BOROHYDRIDE
Belyi, A. A.,Chigladze, L. G.,Rusanov, A. L.,Vol'pin, M. E.
, p. 1801 - 1806 (1989)
As a result of treatment with sodium borohydride, Pd(0)-polyheteroarylene catalysts for the hydrogenation of unsaturated compounds acquire the capability for selective hydrogenation of alkynes as a result of suppressing processes of hydrogen addition to the double bond of the olefins and dienes that are obtained by reduction of the alkynes.
Mechanism of autocatalysis in the thermal dehydrochlorination of poly(vinyl chloride)
Starnes Jr., William H.,Ge, Xianlong
, p. 352 - 359 (2004)
Autocatalysis during the thermal dehydrochlorination of poly(vinyl chloride) (PVC) is shown to be a free-radical process that converts the ordinary monomer units of the polymer into chloroallylic structures that have low thermal stabilities. In the first stage of dehydrochlorination, conjugated polyene sequences are created by a nonfree-radical route. They react with HCl to give cation monoradicals and/or excited cation diradicals. One or both of these species, or other radicals formed them, can then abstract methylene hydrogen in order to produce new radicals that are also carbon-centered. These are converted by chlorine-atom β scission into the chloroallylic segments, which start the growth of new polyenes in the usual (nonradical) way. At 180°C in solid PVC, autocatalysis was inhibited by free-radical scavengers (a hindered phenol, triphenylmethane, and metallic mercury) but greatly enhanced by an increased concentration of HCl when all-trans-β-carotene, a model for PVC polyene sequences, was introduced simultaneously. When the were subjected to autocatalytic conditions, other model compounds gave products that apparently resulted from the abstraction of hydrogen by free-radical intermediates.
Highly selective semi-hydrogenation of alkynes with a Pd nanocatalyst modified with sulfide-based solid-phase ligands
Huang, Lingqi,Hu, Kecheng,Ye, Ganggang,Ye, Zhibin
, (2021/03/30)
Soluble small molecular/polymeric ligands are often used in Pd-catalyzed semi-hydrogenation of alkynes as an efficient strategy to improve the selectivity of targeted alkene products. The use of soluble ligands requires their thorough removal from the reaction products, which adds significant extra costs. In the paper, commercially available, inexpensive, metallic sulfide-based solid-phase ligands (SPL8-4 and SPL8-6) are demonstrated as simple yet high-performance insoluble ligands for a heterogeneous Pd nanocatalyst (Pd@CaCO3) toward the semi-hydrogenation of alkynes. Based on the reactions with a range of terminal and internal alkyne substrates, the use of the solid-phase ligands has been shown to markedly enhance the selectivity of the desired alkene products by efficiently suppressing over-hydrogenation and isomerization side reactions, even during the long extension of the reactions following full substrate conversion. A proper increase in the dosage or a reduction in the average size of the solid-phase ligands enhances such effects. With their insoluble nature, the solid-phase ligands have the distinct advantage in their simple, convenient recycling and reuse while without contaminating the products. A ten-cycle reusability test with the SPL8-4/Pd@CaCO3 catalyst system confirms its well-maintained activity and selectivity over repeated uses. A mechanistic study with x-ray photoelectron spectroscopy indicates that the solid-phase ligands have electronic interactions with Pd in the supported catalyst, contributing to inhibit the binding and further reaction of the alkene products. This is the first demonstration of solid-phase ligands for highly selective semi-hydrogenation of alkynes, which show strong promise for commercial applications.
Ambient Hydrogenation and Deuteration of Alkenes Using a Nanostructured Ni-Core–Shell Catalyst
Beller, Matthias,Feng, Lu,Gao, Jie,Jackstell, Ralf,Jagadeesh, Rajenahally V.,Liu, Yuefeng,Ma, Rui
supporting information, p. 18591 - 18598 (2021/06/28)
A general protocol for the selective hydrogenation and deuteration of a variety of alkenes is presented. Key to success for these reactions is the use of a specific nickel-graphitic shell-based core–shell-structured catalyst, which is conveniently prepared by impregnation and subsequent calcination of nickel nitrate on carbon at 450 °C under argon. Applying this nanostructured catalyst, both terminal and internal alkenes, which are of industrial and commercial importance, were selectively hydrogenated and deuterated at ambient conditions (room temperature, using 1 bar hydrogen or 1 bar deuterium), giving access to the corresponding alkanes and deuterium-labeled alkanes in good to excellent yields. The synthetic utility and practicability of this Ni-based hydrogenation protocol is demonstrated by gram-scale reactions as well as efficient catalyst recycling experiments.