- Iron-Catalyzed Wacker-type Oxidation of Olefins at Room Temperature with 1,3-Diketones or Neocuproine as Ligands**
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Herein, we describe a convenient and general method for the oxidation of olefins to ketones using either tris(dibenzoylmethanato)iron(III) [Fe(dbm)3] or a combination of iron(II) chloride and neocuproine (2,9-dimethyl-1,10-phenanthroline) as catalysts and phenylsilane (PhSiH3) as additive. All reactions proceed efficiently at room temperature using air as sole oxidant. This transformation has been applied to a variety of substrates, is operationally simple, proceeds under mild reaction conditions, and shows a high functional-group tolerance. The ketones are formed smoothly in up to 97 % yield and with 100 % regioselectivity, while the corresponding alcohols were observed as by-products. Labeling experiments showed that an incorporated hydrogen atom originates from the phenylsilane. The oxygen atom of the ketone as well as of the alcohol derives from the ambient atmosphere.
- Kataeva, Olga,Kn?lker, Hans-Joachim,Linke, Philipp,Puls, Florian
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supporting information
p. 14083 - 14090
(2021/05/24)
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- Synthesis of mesoporous ZSM-5 zeolites and catalytic cracking of ethanol and oleic acid into light olefins
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Conversion of biomass-derived chemicals into light olefins is a promising method to maintain sustainable development of light olefin industry. In this study, three mesoporous ZSM-5 zeolites (MZSM-5-A, MZSM-5-B and MZSM-5-C) with major pore diameter about 4.8 nm, 16 nm and 22 nm were synthesized using a hydrothermal method by utilizing different templates. The catalytic activity of catalysts was studied by catalytic cracking of ethanol and oleic acid. The influence of reaction temperature on conversion and product selectivity was investigated. The characterization of ZSM-5 samples showed that the orders of the external surface area and mesopore volume were MZSM-5-C > MZSM-5-B > MZSM-5-A > conventional HZSM-5. In ethanol to light olefin reaction, MZSM-5-C achieved the highest light olefin yield (318.3 mL g?1) and ethylene selectivity (42.3%) at 400 °C. In oleic acid to light olefin reaction, MZSM-5-B achieved a complete conversion of oleic acid at 500 °C, and obtained the highest light olefin selectivity (38.1%) at 550 °C. The difference may be relevant to the size and chemical structure of feedstock molecular as well as the acidity of catalysts. Regardless of ethanol or oleic acid as feedstock, introduction of mesopore in zeolites significantly enhanced the light olefin yield and selectivity.
- Zhao, Tingting,Li, Fuwei,Yu, Hongchang,Ding, Shilei,Li, Zhixia,Huang, Xinyuan,Li, Xiang,Wei, Xiaohan,Wang, Zhenlin,Lin, Hongfei
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p. 101 - 110
(2019/02/24)
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- Conversion of Olefins into Ketones by an Iron-Catalyzed Wacker-type Oxidation Using Oxygen as the Sole Oxidant
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We describe a mild and operationally simple procedure for the oxidation of olefins into ketones. The reaction is catalyzed by the hexadecafluorinated iron–phthalocyanine complex FePcF16 with stoichiometric amounts of triethylsilane as an additive under oxygen atmosphere to give ketones in good to high yields with excellent chemoselectivity and functional group tolerance. Ketone formation proceeds in up to 95 % yield and with 100 % regioselectivity while the corresponding alcohols were observed as side products.
- Puls, Florian,Kn?lker, Hans-Joachim
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supporting information
p. 1222 - 1226
(2018/01/01)
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- Oxidation of heavy 1-olefins (C12= s(-) C20=) with TBHP using a modified Wacker system
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The oxidation of heavy olefins (C12-C20) was carried out using a modified Wacker system with TBHP as oxidant and acetonitrile as solvent at 80 °C. This system allowed the oxidation of 1-octadecene giving rise to 90% conversion with 60% selectivity towards 2-octadecanone after 2 h while the addition of β-cyclodextrins did not increase the production of 2-octadecanone. The oxidation of a equimolar mixture of n-dodecane + 1-dodecene enhanced markedly the selectivity towards 2-dodecanone yielding 63% instead of 34% in the absence of n-paraffin after 2 h, likely due to a dilution effect of the n-dodecane which reduces the extent of the isomerization reactions. The oxidation of a equimolar mixture C12= + C16= + C20= in the presence of equimolar amounts of their corresponding n-paraffins gave rise to practically complete conversion and selectivities toward 2-methylketones within 70-90% enhancing with decreasing chain length due to their higher solubility in the biphasic system. The activity of the catalyst dropped after two reaction cycles indicating its deactivation by the formation of palladium clusters. However, it was possible to obtain similar results in terms of activity and selectivity by increasing the (1-dodecene)/(PdCl2) ratio to 100, which is expected to increase the catalyst lifetime by decreasing the extent of palladium aggregation. In this regard, the reported system is rather promising for the oxidation of heavy 1-olefins towards methyl ketones.
- Escola,Botas,Vargas,Bravo
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experimental part
p. 34 - 39
(2010/06/12)
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- A synthetic approach to the plakoridines modeled on a biogenetic theory
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An expedient synthetic route to the fully substituted pyrrolidine ring system of the plakoridines is described using an approach modeled on a plausible biosynthetic pathway.
- Etchells, Laura L.,Sardarian, Ali,Whitehead, Roger C.
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p. 2803 - 2807
(2007/10/03)
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- Selective Isomerization of 1,2-Epoxyalkanes to Aldehydes with Lithium Dialkylamides
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Reaction of a variety of 1,2-epoxyalkanes with 2.5 equiv. of bulky metal amide - lithium 2,2,6,6-tetramethylpiperidide - affords the corresponding aldehydes exclusively in high yields; this is the first example of base-promoted isomerization of monosubstituted epoxides to aldehydes.
- Yanagisawa, Akira,Yasue, Katsutaka,Yamamoto, Hisashi
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p. 2103 - 2104
(2007/10/02)
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- SODIUM HYDROGEN TELLURIDE AS A USEFUL NUCLEOPHILIC REAGENT FOR THE CLEAVAGE OF EPOXIDES AND OF QUATERNARY AMMONIUM SALTS
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Sodium hydrogen telluride opens many epoxides cleanly by an SN2 process to give telluro-alcohols, which by reduction with nickel boride afford alcohols.An intermediate telluro-alcohol was converted to olefin in high yield by treatment with p-toluene-sulphonyl chloride in pyridine.Quaternary ammonium salts are also cleaved efficiently by sodium hydrogen telluride.
- Barton, Derek H. R.,Fekih, Abdelwaheb,Lusinchi, Xavier
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p. 6197 - 6200
(2007/10/02)
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- THE INVENTION OF NEW RADICAL CHAIN REACTIONS. PART X. HIGH YIELD RADICAL ADDITION REACTIONS OF αβ-UNSATURATED NITROOLEFINS. AN EXPEDIENT CONSTRUCTION OF THE 25-HYDROXY-VITAMIN D3 SIDE CHAIN FROM BILE ACIDS.
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Radicals derived from thiohydroxamic esters 3 readily add to nitroolefins 5 (Z=NO2) to give good yields of α-nitrosulphides.These adducts, where the structure permits, are easily oxidised to carboxylic acids 8 by treatment with alkaline hydrogen peroxide.Reductive cleavage to the corresponding aldehydes or ketones 9 is efficiently carried out by the action of TiCl3.Addition of methyl magnesium iodide to methyl ketone derived from 3α-acetoxy 11-oxo cholanic acid gives steroid 10 possessing the 25-hydroxycholesterol side chain of the vitamin D3 metabolites.Radical additions to 1-phenylthio-2-nitropropene 11 have been briefly studied.
- Barton, Derek H.R.,Togo, Hideo,Zard, Samir Z.
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p. 5507 - 5516
(2007/10/02)
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- Cycloalkanones. 8. Hypocholesterolemic activity of long chain ketones related to pentadecanone
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Aliphatic analogs of 2,8 dibenzylcyclooctanone which included C15-C18 ketones have been investigated for hypocholesterolemic activity in rats. The position of the carbonyl group in the chain for maximum activity appears to be the 2 position. 2 Hexadecanone reduced serum cholesterol levels significantly without altering serum triglyceride levels. This drug was not estrogenic at effective doses which is in contrast to the cyclooctanones which possess this activity.
- Wyrick,Hall,Piantadosi,Fenske
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p. 219 - 222
(2007/10/12)
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