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Süss-Fink, Georg

Nom
Süss-Fink, Georg
Affiliation principale
Fonction
Professeur ordinaire
Email
georg.suess-fink@unine.ch
Identifiants
https://libra.unine.ch/handle/123456789/385

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  • Publication
    Métadonnées seulement
    Regioselective alkane oxygenation with H2O2 catalyzed by titanosilicalite TS-1
    (2006)
    Shul'pin, Georgiy B
    ;
    Sooknoi, Tawan
    ;
    Romakh, Vladimir B
    ;
    Süss-Fink, Georg 
    ;
    Shul'pina, Lidia S
    Titanosilicalite TS-1 catalyses oxidation of light (methane, ethane, propane and n-butane) and normal higher (hexane, heptane, octane and nonane) alkanes to give the corresponding isomeric alcohols and ketones. The oxidation of higher alkanes proceeds in many cases with a unique regioselectivity. Thus, in the reaction with n-heptane the CH2 groups in position 3 exhibited a reactivity 2.5 times higher than those of the other methylene groups. This selectivity can be enhanced if hexan-3-ol is added to the reaction mixture, the 3-CH2/2-CH2 ratio becoming 10. It is assumed that the unusual selectivity in the oxidation of n-heptane (and other higher alkanes) is due to steric hindrance in the catalyst cavity. As a result, the catalytically active species situated on the catalyst walls can only easily react with certain methylenes of the alkane, which is adsorbed in the cavity taking U-shape (hairpin) conformations. (c) 2006 Elsevier Ltd. All rights reserved.
  • Publication
    Métadonnées seulement
    Alkane oxygenation with H2O2 catalysed by FeCl3 and 2,2 '-bipyridine
    (2005)
    Shul'pin, Georgiy B
    ;
    Golfeto, Camilla C
    ;
    Süss-Fink, Georg 
    ;
    Shul'pina, Lidia S
    ;
    Mandelli, Dalma
    The H2O2-FeCl3-bipy system in acetonitrile efficiently oxidises alkanes predominantly to alkyl hydroperoxides. Turnover numbers attain 400 after 1 h at 60 degrees C. It has been assumed that bipy facilitates proton abstraction from a H2O2 molecule coordinated to the iron ion (these reactions are stages in the catalytic cycle generating hydroxyl radicals from the hydrogen peroxide). Hydroxyl radicals then attack alkane molecules finally yielding the alkyl hydroperoxide. (c) 2005 Elsevier Ltd. All rights reserved.
  • Publication
    Métadonnées seulement
    Hydrogen peroxide oxidation of saturated hydrocarbons catalyzed by osmium compounds
    (2002)
    Shul'pin, Georgiy B
    ;
    Süss-Fink, Georg 
    Osmium derivatives, in particular OsCl3, catalyze the effective oxidation of saturated hydrocarbons in acetonitrile. The products formed are a ketone (aldehyde) and an alcohol. The addition of nitrogen heterocycles, such as pyridine, accelerated the reaction and increased the product yields. The ketone (aldehyde)/alcohol ratio dramatically changed in this case. In the presence of pyridine, the reaction occurred stereoselectively. The suggested reaction mechanism includes hydrogen atom abstraction from an alkane by an osmium oxo compound, resulting in the formation of the alkyl radical, which yields the alkylperoxyl radical after addition of an oxygen molecule. The latter radical degrades in the presence of the osmium complex under reaction conditions to give a ketone (aldehyde) and an alcohol.
  • Publication
    Métadonnées seulement
    Alkane oxygenation catalysed by gold complexes
    (2001)
    Shul'pin, Georgiy B
    ;
    Shilov, Alexander E
    ;
    Süss-Fink, Georg 
    Gold(III) and gold(I) complexes, NaAuCl4 and ClAuPPh3, efficiently catalyse the oxidation of alkanes by H2O2 in acetonitrile solution at 75 degreesC. Turnover numbers (TONs) attain 520 after 144 h. Alkyl hydroperoxides are the main products, whereas ketones (aldehydes) and alcohols are formed in smaller concentrations. It is suggested on the basis of the bond selectivity study that at least one of the pathways in Au-catalysed alkane hydroperoxidation does not involve the participation of free hydroxyl radicals. Possibly, the oxidation begins from the alkane hydrogen atom abstraction by a gold oxo species. The oxidation of cyclooctane by air at room temperature catalysed by NaAuCl4 in the presence of Zn/CH3COOH as a reducing agent and methylviologen as an electron-transfer agent gave cyclooctanol (TON = 10). (C) 2001 Published by Elsevier Science Ltd.
  • Publication
    Métadonnées seulement
    Oxidations by the system "hydrogen peroxide-manganese(IV) complex-carboxylic acid" Part 3. Oxygenation of ethane, higher alkanes, alcohols, olefins and sulfides
    (2001)
    Shul'pin, Georgiy B
    ;
    Süss-Fink, Georg 
    ;
    Shul'pina, Lidia S
    The manganese(IV) complex salt [L2Mn2O3](PF6)(2) (L = 1,4,7-trimethyl-1,4,7-triazacyclononane) (compound 1, see Scheme 1) very efficiently catalyzes the hydroperoxidation of saturated hydrocarbons, including ethane by H2O2 in acetontitrile or nitromethane solution at low (room or lower) temperature, provided a carboxylic (typically acetic) acid is present. The hydroperoxidation of tertiary positions in disubstituted cyclohexanes proceeds with partial retention of configuration in nitromethane or acetonitrile solution, while the stereoselectivity of the reaction is only negligible in acetone solution. The system "H2O2-compound 1-MeCO2H" also transforms secondary alcohols into the corresponding ketones with quantitative yields at room temperature within a few minutes; the yields of aldehydes and carboxylic acids in the oxidation of primary alcohols are lower. Terminal aliphatic olefins such as hexene-1 are quantitatively epoxidized by the same system in acetonitrile at room temperature within 20 min, while the epoxide yield in the analogous reaction with styrene attains only 60% under the same conditions. Finally, dimethylsulfide can be quantitatively and selectively converted into dimethylsulfoxide within 3h at room temperature. The system "tert-BuOOH-compound 1" also oxidizes alkanes, addition of acetic acids has less pronounced effect on the direction and efficiency of the reaction, Two other checked derivative of Mn(IV) (compounds 2 and 3) as well a porphyrin complex of Mn(III) (compound 4) exhibited lower activity in catalysis of alkane oxidation with tert-BuOOH. (C) 2001 Elsevier Science B.V. All rights reserved.
  • Publication
    Métadonnées seulement
    Oxidations by the system "hydrogen peroxide manganese(IV) complex acetic acid" - Part II. Hydroperoxidation and hydroxylation of alkanes in acetonitrile
    (1999)
    Shul'pin, Georgiy B
    ;
    Süss-Fink, Georg 
    ;
    Smith, J R Lindsay
    Higher alkanes (cyclohexane, n-pentane, n-heptane, methylbutane, 2- and 3-methylpentanes, 3-methylhexane, cis- and trans-decalins) are oxidized at 20 degrees C by H2O2 in air in acetonitrile (or nitromethane) solution in the presence of the manganese(IV) salt [L2Mn2O3](PF6)(2) (L = 1,4,7-trimethyl-1,4-7-triazacyclononane) as the catalyst. An obligatory component of the reaction mixture is acetic add. Turnover numbers attain 3300 after 2 h, the yield of oxygenated products is 468 based on the alkane. The oxidation affords initially the corresponding alkyl hydroperoxide as the predominant product, however later these compounds decompose to produce the corresponding ketones and alcohols. Regio- and bond selectivities of the reaction are high: C(1) : C(2) : C(3) : C(4) approximate to 1 : 40 : 35 : 35 and 1 degrees : 2 degrees : 3 degrees is 1 : (15-40) : (180-300). The reaction with both. isomers of decalin gives (after treatment with PPh3) alcohols hydroxylated in the tertiary positions with the cis/trans ratio of similar to 2 in the case of cis-decalin, and of similar to 30 in the case of trans-decalin (i.e. in the latter case the reaction is stereospecific). Light alkanes (methane, ethane, propane, normal butane and isobutane) can be also easily oxidized by the same reagent in acetonitrile solution, the conditions being very mild: low pressure (1-7 bar of the alkane) and low temperature (-22 to +27 degrees C). Catalyst turnover numbers attain 3100, the yield of oxygenated products is 22% based on the alkane. The yields of oxygenates are higher at low temperatures. The ratio of products formed (hydroperoxide : ketone : alcohol) depends very strongly on the conditions of the reaction and especially on the catalyst concentration (at higher catalyst concentration the ketone is predominantly produced). (C) 1999 Elsevier Science Ltd. All rights reserved.