870-10-0

Unsaturated fatty esters can be easily transformed into ketoesters through a two-step process. The highly efficient epoxidation is carried out with tert-butyl hydroperoxide (TBHP) in α,α,α-trifluorotoluene (TFT) using a Ti-silica heterogeneous catalyst. The formed epoxide is easily rearranged by a heterogeneous Br?nsted acid, with Nafion-silica SAC13 as the most efficient one. Both reactions can be combined in a tandem process, with separation of the Ti-silica catalyst by filtration from the reaction medium and addition of the second acid catalyst to perform the second reaction. Each catalyst is separated individually and can be reused, with or without re-activation, under the same conditions to maximize the productivity.

Utilization of renewable biomass to partly replace the fossil resources in industrial applications has attracted attention due to the limited fossil feedstock with the increased environmental concerns. This work introduced a modified Wacker-type oxidation for transformation of unsaturated fatty acids/esters to the corresponding keto fatty acids/esters, in which Cu2+ cation was replaced with common nonredox metal ions, that is, a novel Pd(II)/Lewis acid (LA) catalyst. It was found that adding nonredox metal ions can effectively promote Pd(II)-catalyzed oxidation of unsaturated fatty acids/esters to the corresponding keto fatty acids/esters, even much better than Cu2+, and the promotional effect is highly dependent on the Lewis acidity of added nonredox metal ions. The improved catalytic efficiency is attributed to the formation of heterobimetallic Pd(II)/LA species, and the oxidation mechanism of this Pd(II)/LA catalyst is also briefly discussed.

Herein, the preparation of methyl oleate α-hydroxyketone from the corresponding 1,2-diol was investigated using both homogeneous and heterogeneous systems. Homogeneous conditions using a Pd(OAc)2/neocuproine complex were first developed using oxygen as a sole oxidant under mild conditions (MeOH, 50 °C). Under these conditions, the conversion of diol reached 95%, and α-hydroxyketone was obtained with 97% selectivity. The access to α-hydroxyketone has also been studied by dehydrogenation using a range of heterogeneous catalysts under solvent-free conditions at high temperatures (160-180 °C). Dehydrogenation using activated Ru/C under vacuum provided α-hydroxyketone with 93% conversion and 82% GC yield. The optimized conditions were applied to a range of oleochemical diols, including a vegetable oil derivative, to obtain the corresponding α-hydroxyketones with up to 74% isolated yields.

A process for preparing a carboxylic acid, including a step of bringing at least one vicinal diol or at least one vicinal polyol into contact with an atmosphere including oxygen, and a catalyst, and in the absence of additional solvent.

A series of amphiphilic 1-alkyl-3-methylimidazolium hydrogen sulfate ionic liquids were synthesized. Acidic hydrogen sulfate ionic liquids with the alkyl chains C6-C14 are characterized by good surface properties. Their surface properties (adsorption and micellization parameters, degree of ionization of micelles, Krafft temperatures and thermodynamic parameters) were determined. Synthesized ionic liquids were applied as a co-catalyst in an oxirane ring opening reaction in epoxidized fatty acid methyl esters (FAME). Their co-catalytic activities were determined and discussed as a function of their structure and surface properties. It was found that the co-catalytic properties, both conversion and selectivity, of alkylimidazolium hydrogen sulfate ionic liquids noticeably depended on the alkyl chain lengths, and in consequence their properties.

Epoxidation of vegetable oils or fatty acid methyl esters (FAMEs) produce important monomers which are widely used as plasticizers or stabilizers in the polymer industry. However, little attention has been focused on the influence of the alkenyl structure of the fatty acid on the efficiency and selectivity of their epoxidation. In this work, the influence of the alkenyl structure (the number of double bonds) of the FAMEs on the epoxidation reaction has been investigated. Three model FAMEs with 1 to 3 double bonds were epoxidized using both a weak (formic acid) and a strong (sulfuric acid/acetic acid) acid system. It was found that FAMEs with more double bonds have higher reactivities toward the epoxidation reaction. In addition, the electron-donating effect of the double bonds on the fatty acid chain tends to stabilize the resulting epoxide adjacent to it with the weak acid system. Furthermore, FAMEs with more double bonds easily undergo side reactions with the strong acid system (H2SO4). Epoxidation of two vegetable oils with different fatty acid compositions were carried out with the same two acid catalyst systems. And the results were in agreement with those from the FAMEs. The current findings could provide useful guidance for the epoxidation of different vegetable oils with different alkenyl structure compositions.

The epoxidation of the unsaturated fatty acid methyl esters (FAME) in biodiesel with H2O2 was investigated at 323 K in the liquid phase over microporous nano-sized TS-1 as well as micro-/mesoporous nano-sized TS-1. Nano-sized TS-1 with stacked morphology exhibits a catalytic activity per number of Ti sites up to 30% higher than a conventional, industrial TS-1 catalyst. Mesoporosity was successfully introduced by a desilication-recrystallization approach. Desilication by alkaline treatment in the presence of the structure-directing agent tetrapropylammonium cation (TPA+) or NaOH leads to the generation of undefined mesopores (10-40 nm), probably accompanied by an increase of the surface hydrophilicity. Consequently, the alkaline-treated materials show a two times lower catalytic activity in the epoxidation of biodiesel than the purely microporous parent material. The surfactant-assisted recrystallization of the alkaline-treated materials results in more uniform and smaller mesopores (3-10 nm). In the epoxidation, the recrystallized materials are remarkably more active with respect to both the purely microporous parent and alkaline-treated materials reaching a FAME conversion of 65% with an epoxide selectivity of 82%.

An efficient and environmentally benign strategy for the oxyfunctionalization of fatty acid methyl esters (FAMEs) employing molecular oxygen as an oxidizing agent is described. Keto-fatty acid esters were directly synthesized by co-catalyst-free Wacker oxidations employing oxygen as a sole re-oxidant. Amine functionalization of the thus obtained keto-fatty acid esters was achieved by reductive amination. The prepared renewable AB-type monomers were studied in homopolymerizations as well as in copolymerization reactions with hexamethylendimethylamine and dimethyl adipate to modify the properties of conventional Nylon 6,6. The obtained (co)-polymers were characterized by SEC, NMR and DSC analysis as well as water uptake tests. the Partner Organisations 2014.

The present invention is directed to methods for oxidizing internal olefins to ketones. In various embodiments, each method comprising contacting an organic substrate, having an initial internal olefin, with a mixture of (a) a biscationic palladium salt; and (b) an oxidizing agent; dissolved or dispersed in a solvent system to form a reaction mixture, said solvent system comprising at least one C2-6 carbon nitrile and optionally at least one secondary alkyl amide, said method conducted under conditions sufficient to convert at least 50 mol % of the initial internal olefin to a ketone, said ketone positioned on a carbon of the initial internal olefin. The transformation occurs at room temperature and shows wide substrate scope. Applications to the oxidation of seed oil derivatives and a bioactive natural product are described.

Make it simple! A convenient and general palladium-catalyzed oxidation of internal olefins to ketones is reported. The transformation occurs at room temperature and shows wide substrate scope. Applications to the oxidation of seed-oil derivatives and a bioactive natural product (see scheme) are described, as well as intriguing mechanistic features. Copyright

Titanium-silica catalysts, obtained by grafting titanocene dichloride onto mesoporous silica (MCM-41 and MCM-48) and onto nanosized pyrogenic silica, were tested in the epoxidation of methyl oleate using aqueous hydrogen peroxide. All titanium-containing materials, combined with the slow addition of hydrogen peroxide, showed good catalytic activity and comparable behaviour in terms of conversion, selectivity and yield of methyl epoxystearate, notwithstanding the morphology and the texture of the silica support. By optimizing the reaction conditions (especially, the catalyst to substrate ratio), high yields up to 91% in epoxide were obtained for Ti/MCM-41 with a high stereoselectivity (80%) for the cis-epoxide. The formation of the cis/trans-epoxide and the nature of the catalytic reaction pathway are also discussed.

The acid-catalysed reaction of methyl 9,10-epoxystearate ring opening using synthetic saponite acid clay as catalyst, has been studied for the first time. In the presence of methanol, 90% of the epoxide substrate is converted after 5 min and the main reaction product is the vicinal hydroxyether, methyl methoxyhydroxystearate, with 84% of selectivity. In the absence of alcohol the ring opening reaction proceeds slower, leading to a mixture of methyl 9- and 10-oxostearate as main products, and a 9,10-epoxystearate conversion of 66% after 1 h. The performance of acid saponite, an environmentally benign catalyst, is exceedingly higher than those of strong mineral acids, such as H 2SO4, widely used for this reaction.

Oxidation of unsaturated fatty esters to the corresponding oxo derivatives was accomplished in moderate to high yields when the substrates were treated with palladium(II) chloride and p-benzoquinone in aqueous tetrahydrofuran (THF/H2O, 4:1 v/v) under ultrasound (20 kHz).Methyl 10-undecanoate furnished methyl 10-oxoundecanoate in 92percent yield.Methyl oleate and trans-2-hexadecenoate furnished methyl 9(10)-oxostearate (65percent) and methyl 3-oxohexadecanoate (41percent) respectively.Unsaturated fatty esters with a terminal double bond were more readily oxidized than those containing an internal double bond.Methyl trans-3,12-tridecadienoate gave only methyl 12-oxo-trans-3-tridecenoate (86percent), while a cyclopentenoic fatty ester (methyl chaulmoograte) furnished a mixture of positional oxo-isomers: viz. methyl 1-oxocyclopentane-2-tridecanoate and 1-oxocyclopentane-3-tridecanoate (51.5percent total).Oxidation of methyl 12-hydroxy-, 12-azido-, 12-chloro- and 12-oxo-cis-9-octadecanoate furnished the corresponding 9-oxo-derivatives only.Methyl iso-ricinoleate (methyl 9-hydroxy-cis-12-octadecenoate) gave exclusively methyl 9-hydroxy-12-oxostearate.Without ultrasonication the same oxidation reactions at room temperature furnished low yields (30percent) of the corresponding oxo derivatives after prolonged stirring at room temperature.Aqueous THF is a superior solvent system than the commonly used aqueous N,N-dimethylformmaide (DMF). - Keywords: Aqueous THF; p-Benzoquinone; Oxidation; Oxo fatty esters; Palladium(II) chloride; Ultrasound; Unsaturated fatty esters; Wacker reaction

Silver chromate-iodine has been used for the direct synthesis of α-iodohydrins from olefins for which a mechanism has been proposed.Terminal (1) and internal (5) olefinic esters on treatment with silver chromate-iodine under anhyd. conditions yield the ex

-

Corynebacterium sp.S-401 was isolated from soil using squalene as carbon source.Microbiological properties of this bacterium are described.The five metabolic products of this bacterium from squalene were indentified as mono-, di-, tri-, tetra-, and pentahydrated squalene.The resting cells of the bacterium catalyzed the hydration of oleic acid to give (-)-10R-hydroxyoctadecanoic acid and further oxidized product, 10-oxooctadecanoic acid, was also isolated from the reaction mixture.