- One-pot synthesis of 2-alkyl cycloketones on bifunctional Pd/ZrO2 catalyst
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2-Alkyl cycloketones are essential chemicals and intermediates for synthetic perfumes and pesticides, which are conventionally produced by multistep process including aldol condensation, separation and hydrogenation. In present work, a batch one-pot cascade approach using aldehydes and cycloketones as the raw materials, and a bifunctional Pd/ZrO2 catalyst was developed for the synthesis of 2-alkyl cycloketones, e.g., cyclohexanone and cycloheptanone. Very high aldehydes (except for paraldehyde with large steric hindrance) conversion and high yields for 2-alkyl cycloketones (e.g., 99 % of conversion for n-butanal and 76 wt.% of yield for 2-butyl cyclohexanone) were obtained at mild temperature of 140 °C. After 10 cycles of reuse, Pd/ZrO2 catalyst showed slight deactivation (ca. 5 % conversion and 10 % yield losses), due to the coke on the catalyst. However, the performance of the catalyst was completely recovered after an oxidative regeneration.
- Xue, Weiyang,Gu, Bin,Wu, Huiling,Liu, Mengyang,He, Songbo,Li, Jingmei,Rong, Xin,Sun, Chenglin
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- Branched-Selective Direct α-Alkylation of Cyclic Ketones with Simple Alkenes
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Herein, we describe an intermolecular direct branched-selective α-alkylation of cyclic ketones with simple alkenes as the alkylation agents. Through an enamine-transition metal cooperative catalysis mode, the α-alkylation is realized in an atom- and step-economic manner with excellent branched selectivity for preparing β-branched ketones. Employment of a pair of bulky Br?nsted acid and base as additives is responsible for enhanced efficiency. Promising enantioselectivity (74 % ee) has been obtained. Experimental and computational mechanistic studies suggest that a pathway through alkene migratory insertion into the Ir?C bond followed by C?H reductive elimination is involved for the high branched selectivity.
- Xing, Dong,Dong, Guangbin,Qi, Xiaotian,Marchant, Daniel,Liu, Peng
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supporting information
p. 4366 - 4370
(2019/05/30)
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- Thermal Degradation of Aviation Synthetic Lubricating Base Oil
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The thermal degradation, under oxidative pyrolysis conditions, of two synthetic lubricating base oils, poly-α-olefin (PAO) and di-ester (DE), was investigated. The main objective of the study was to characterize their behavior in simulated “areo-engine” conditions, i.e. compared the thermal stability and identified the products of thermal decomposition as a function of exposure temperature. Detailed characterizations of products were performed with Fourier transform infrared spectrometry (FTIR), gas chromatography/ mass spectrometry (GC/MS), viscosity experiments and four-ball tests. The results showed that PAO had the lower thermal stability, being degraded at 200°C different from 300°C for DE. The degradation also effected the tribological properties of lubricating oil. Several by-products were identified during the thermal degradation of two lubricants. The majority of PAO products consisted of alkanes and olefins, while more oxygen-containing organic compounds were detected in DE samples according to the observation of GC/MS analysis. The related reaction mechanisms were discussed according to the experimental results.
- Wu, Nan,Zong, Zhimin,Fei, Yiwei,Ma, Jun,Guo, Feng
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p. 250 - 257
(2018/04/09)
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- Process for the preparation of organic compounds with manganese cataylsts or the like
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A process of the present invention produces an organic compound by allowing a compound containing an electron attractive group of following Formula (1): 1wherein Y is an electron attractive group; and Rb and Rc are each a hydrogen atom or an organic group, where Y, Rb and Rc may respectively be combined with each other to form a ring with an adjacent carbon atom, to react with a compound containing an unsaturated carbon-carbon bond of following Formula (2) or 2wherein Rd, Re, Rf, Rg, Ri and Rj are each a hydrogen atom or an organic group, where Rd, Re, Rf and Rg may respectively be combined to form a ring with one or two adjacent carbon atoms, and Ri and Rj may be combined to form a ring with adjacent two carbon atoms, in the presence of oxygen and a catalytic compound of a Group 5, 6, 7, 8 or 9 element of the Periodic Table of Elements to yield a compound of following Formula (3) or (8): 3wherein Z is a hydrogen atom or a hydroxyl group; and Y, Rb, Rc, Rd, Re, Rf, Rg, Ri and Rj have the same meanings as defined above. This process can efficiently produce a compound having an alkyl group or alkenyl group bonded at the alpha position of an electron attractive group, or a derivative thereof, by catalytic radical addition reaction.
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- PROCESS FOR THE PREPARATION OF ORGANIC COMPOUNDS WITH MANGANESE CATALYSTS OR THE LIKE
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A process of the present invention produces an organic compound by allowing a compound containing an electron attractive group of following Formula (1):wherein Y is an electron attractive group; and Rb and Rc are each a hydrogen atom or an organic group, where Y, Rb and Rc may respectively be combined with each other to form a ring with an adjacent carbon atom, to react with a compound containing an unsaturated carbon-carbon bond of following Formula (2) or (7):wherein Rd, Re, Rf, Rg, Ri and Rj are each a hydrogen atom or an organic group, where Rd, Re, Rf and Rg may respectively be combined to form a ring with one or two adjacent carbon atoms, and Ri and Rj may be combined to form a ring with adjacent two carbon atoms, in the presence of oxygen and a catalytic compound of a Group 5, 6, 7, 8 or 9 element of the Periodic Table of Elements to yield a compound of following Formula (3) or (8):wherein Z is a hydrogen atom or a hydroxyl group; and Y, Rb, Rc, Rd, Re, Rf, Rg, Ri and Rj have the same meanings as defined above. This process can efficiently produce a compound having an alkyl group or alkenyl group bonded at the alpha position of an electron attractive group, or a derivative thereof, by catalytic radical addition reaction.
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- Catalytic radical addition of ketones to alkenes by a metal-dioxygen redox system
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Radical addition of ketones to alkenes catalyzed by Mn(OAc)2 combined with Co(OAc)2 using dioxygen as oxidant was developed; for instance, the reaction of cyclohexanone with oct-1-ene in the presence of very small amounts of Mn(OAc)2 and Co(OAc)2 under air (1 atm) gave 2-octylcyclohexanone in good selectivity; from styrene, a six-membered cyclic peroxide was isolated in good yield.
- Iwahama,Sakaguchi,Ishii
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p. 2317 - 2318
(2007/10/03)
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- A Cyclopentanone Annulation via Intramolecular Acylation of Alkylsilanes
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A facile construction of cyclopentanones is achieved via ring closure of 5-(trimethylsilyl)alkanoyl chlorides under the influence of AlCl3.
- Urabe, Hirokazu,Kuwajima, Isao
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p. 1140 - 1141
(2007/10/02)
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