- Manganese-catalyzed selective oxidation of aliphatic C-H groups and secondary alcohols to ketones with hydrogen peroxide
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An efficient and simple method for selective oxidation of secondary alcohols and oxidation of alkanes to ketones is reported. An in situ prepared catalyst is employed based on manganese(II) salts, pyridine-2-carboxylic acid, and butanedione, which provides good-to-excellent conversions and yields with high turnover numbers (up to 10 000) with H2O2 as oxidant at ambient temperatures. In substrates bearing multiple alcohol groups, secondary alcohols are converted to ketones selectively and, in general, benzyl C-H oxidation proceeds in preference to aliphatic C-H oxidation. Manganeasy! MnII, picolinic acid, and butanedione make a smart mix for oxidation of secondary alcohols and alkanes and especially benzylic groups to ketones at room temperature with near stoichiometric amounts of hydrogen peroxide, low catalyst loadings, and high turn-over numbers. Copyright
- Dong, Jia Jia,Unjaroen, Duenpen,Mecozzi, Francesco,Harvey, Emma C.,Saisaha, Pattama,Pijper, Dirk,De Boer, Johannes W.,Alsters, Paul,Feringa, Ben L.,Browne, Wesley R.
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p. 1774 - 1778
(2013/10/21)
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- An unusual dimerization of primary unsaturated alcohols catalyzed by RuHCl(CO)(PPh3)3
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When primary unsaturated alcohols were treated with a catalytic amount of RuHCl(CO)(PPh3)3 in benzene under reflux, dimerization reactions took place to give α-hydroxymethyl ketones as major product. The Royal Society of Chemistry 2006.
- Doi, Takashi,Fukuyama, Takahide,Minamino, Satoshi,Husson, Guillaume,Ryu, Ilhyong
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p. 1875 - 1877
(2008/03/14)
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- RuHCl(CO)(PPh3)3-catalyzed reductive dimerization of α,β-unsaturated aldehydes leading to α-hydroxymethyl ketones
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The reductive dimerization α,β-unsaturated aldehydes to give saturated ketones was achieved using RuHCl(CO)(PPh3)3 as a catalyst in the presence of secondary alcohols as hydrogen source. The reaction is likely to proceed via the hydroruthenation of α,β-unsaturated aldehydes followed by aldol reaction of the resultant ruthenium enolates with α,β-unsaturated aldehydes to give unsaturated α-hydroxymethyl ketones, which undergo transfer hydrogenation to give α-hydroxymethyl ketones. Georg Thieme Verlag Stuttgart.
- Doi, Takashi,Fukuyama, Takahide,Minamino, Satoshi,Ryu, Ilhyong
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p. 3013 - 3016
(2008/02/12)
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- Mono-substituted Keggin-polyoxometalate complexes as effective and recyclable catalyst for the oxidation of alcohols with hydrogen peroxide in biphasic system
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Mono-substituted Keggin-polyoxymetalate complex Na6 [SiW 11ZnH2O40]?12H2O was demonstrated to be an effective catalyst for the selective oxidation of alcohols in the presence of hydrogen peroxide as oxidant. The reaction was carried out in an aqueous/oil biphasic system, which allowed easy recovery of catalyst, under relative mild conditions. The catalyst could be reused five times without appreciable loss of activity.
- Wang, Jianmin,Yan, Liang,Li, Guixian,Wang, Xiaolai,Ding, Yong,Suo, Jishuan
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p. 7023 - 7027
(2007/10/03)
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- Aqueous biphasic oxidation: A water-soluble polyoxometalate catalyst for selective oxidation of various functional groups with hydrogen peroxide
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A "sandwich" type polyoxometalate, Na12[(WZn 3(H2O)2][(ZnW9O34) 2], was used as an oxidation catalyst in aqueous biphasic reaction media to effect oxidation of alcohols, diols, pyridine derivatives, amines and aniline derivatives with hydrogen peroxide. The catalyst was shown by 183W NMR to be stable in aqueous solutions in the presence of H 2O2 and showed only minimal non-productive decomposition of the oxidant. Secondary alcohols were selectively oxidized to ketones, while primary alcohols tended to be oxidized to the corresponding carboxylic acids, although secondary alcohols were selectively oxidized in the presence of primary alcohols. Vicinal diols yielded carbon-carbon bond cleavage products in very high yields. Pyridine derivatives were oxidized to the respective TV-oxides, but strongly electron-withdrawing moieties inhibited the oxidation reaction. Primary amines were oxidized to the oximes, but significantly hydrolyzed in situ. Aniline derivatives were oxidized to the corresponding azoxy or nitro products depending on the substitution pattern in the aromatic ring. Catalyst recovery and recycle was demonstrated.
- Sloboda-Rozner, Dorit,Witte, Peter,Alsters, Paul L.,Neumann, Ronny
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p. 339 - 345
(2007/10/03)
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- A water-soluble and "self-assembled" polyoxometalate as a recyclable catalyst for oxidation of alcohols in water with hydrogen peroxide
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We have demonstrated that a simply prepared water-soluble polyoxometalate, Na12[WZnZn2(H2O)2(ZnW9O34)2], synthesized from readily available zinc and tungsten salts in the presence of nitric acid, is an effective catalyst for selective alcohol oxidation with hydrogen peroxide in biphasic (water-alcohol) reaction media. Experiments have shown that the "self-assembled" catalyst in its mother liquor was as active as the isolated catalyst. The aqueous catalyst solution is easily separated from the water-insoluble products and can be recycled without loss in activity or selectivity. Copyright
- Sloboda-Rozner, Dorit,Alsters, Paul L.,Neumann, Ronny
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p. 5280 - 5281
(2007/10/03)
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- Catalytic Conversions in Water. Part 21: Mechanistic Investigations on the Palladium-Catalysed Aerobic Oxidation of Alcohols in Water
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Water-soluble complexes of palladium(II) with phenanthroline-derivatives are stable, recyclable catalysts for the selective aerobic oxidation of a wide range of alcohols to aldehydes, ketones, and carboxylic acids in a biphasic liquid-liquid system. The active catalyst is a dihydroxy-bridged palladium dimer. Kinetics of the reaction, ligand and anion effects are discussed.
- Ten Brink, Gerd-Jan,Arends, Isabel W. C. E.,Sheldon, Roger A.
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p. 355 - 369
(2007/10/03)
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