7108-21-6Relevant academic research and scientific papers
Efficient ruthenium-catalysed oxidative cleavage of methyl oleate with hydrogen peroxide as oxidant
Behr, Arno,Tenhumberg, Nils,Wintzer, Andreas
, p. 172 - 180 (2013)
The oxidative cleavage of alkenes leads to the formation of carboxylic acids. One of the few technical processes using this reaction is the production of azelaic acid via the ozonolysis of oleic acid. Because of the need for stoichiometric amounts of the expensive oxidant ozone, together with safety hazards, there is still a requirement for a catalytic process using a cheap and environmentally friendly oxidant. In the present work, the oxidative cleavage of methyl oleate by hydrogen peroxide was catalysed by an easily available ruthenium precursor with dipicolinic acid as ligand. The systematic optimisation of the reaction led to the formation of azelaic acid monomethyl ester in high yields amounting to 86%. The investigation of the reaction pathway showed that the reaction proceeds via a tandem reaction of epoxidation and hydrolysis of the epoxide and oxidative cleavage of the vic-diol. The Royal Society of Chemistry.
Biobased Aldehydes from Fatty Epoxides through Thermal Cleavage of β-Hydroxy Hydroperoxides**
De Dios Miguel, Thomas,Duc Vu, Nam,Lemaire, Marc,Duguet, Nicolas
, p. 379 - 386 (2020/11/30)
The ring-opening of epoxidized methyl oleate by aqueous H2O2 has been studied using tungsten and molybdenum catalysts to form the corresponding fatty β-hydroxy hydroperoxides. It was found that tungstic acid and phosphotungstic acid gave the highest selectivities (92–93 %) towards the formation of the desired products, thus limiting the formation of the corresponding fatty 1,2-diols. The optimized conditions were applied to a range of fatty epoxides to give the corresponding fatty β-hydroxy hydroperoxides with 30–80 % isolated yields (8 examples). These species were fully characterized by 1H and 13C NMR spectroscopy and HPLC-HRMS, and their stability was studied by differential scanning calorimetry. The thermal cleavage of the β-hydroxy hydroperoxide derived from methyl oleate was studied both in batch and flow conditions. It was found that the thermal cleavage in flow conditions gave the highest selectivity towards the formation of aldehydes with limited amounts of byproducts. The aldehydes were both formed with 68 % GC yield, and nonanal and methyl 9-oxononanoate were isolated with 57 and 55 % yield, respectively. Advantageously, the overall process does not require large excess of H2O2 and only generates water as a byproduct.
A Two-Step Oxidative Cleavage of 1,2-Diol Fatty Esters into Acids or Nitriles by a Dehydrogenation–Oxidative Cleavage Sequence
Guicheret, Boris,Bertholo, Yann,Blach, Philippe,Raoul, Yann,Métay, Estelle,Lemaire, Marc
, p. 3431 - 3437 (2018/09/06)
Dehydrogenative oxidation of vicinal alcohols catalyzed by a commercially 64 wt.% Ni/SiO2 catalyst leads to the formation of α-hydroxyketone. This first step was developed without additional solvent according to two protocols: “under vacuum” or “with an olefin scavenger”. The synthesis of ketols was carried out with good conversions and selectivities. The recyclability of the supported nickel was also studied. Acyloin was then cleaved with oxidative reagent “formic acid/hydrogen peroxide”, which is cheap and can be used on a large scale for industrial oxidation processes. The global yield of this sequential system was up to 80 % to pelargonic acid and azelaic acid monomethyl ester without intermediate purification. By treating the acyloin intermediate with hydroxylamine, nitriles were obtained with a good selectivity.
Homogeneous and heterogeneous catalytic (dehydrogenative) oxidation of oleochemical 1,2-diols to α-hydroxyketones
Vu, Nam Duc,Guicheret, Boris,Duguet, Nicolas,Métay, Estelle,Lemaire, Marc
, p. 3390 - 3399 (2017/07/28)
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.
