- A Two-Step Oxidative Cleavage of 1,2-Diol Fatty Esters into Acids or Nitriles by a Dehydrogenation–Oxidative Cleavage Sequence
-
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.
- Guicheret, Boris,Bertholo, Yann,Blach, Philippe,Raoul, Yann,Métay, Estelle,Lemaire, Marc
-
p. 3431 - 3437
(2018/09/06)
-
- Efficient ruthenium-catalysed oxidative cleavage of methyl oleate with hydrogen peroxide as oxidant
-
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.
- Behr, Arno,Tenhumberg, Nils,Wintzer, Andreas
-
p. 172 - 180
(2013/04/23)
-
- Nitration of Olefinic and Acetylenic Fatty Acid Esters
-
Methyl 10-undecenoate (I) on treatment with fuming nitric acid, sodium nitrite and gl. acetic acid produces two nitro-olefins in minor amounts characterized as methyl 11-nitro-10-undecenoate (II) and methyl 10-nitro-10-undecenoate (III) and major product, methyl 11-hydroxy-10-nitroundecanoate (IV).Under similar conditions, methyl 10-undecynoate (Va) produces methyl 11-nitro-10-oxoundecanoate (VI) and methyl 9-undecynoate (Vb) furnishes methyl 10-nitro-9-oxoundecanoate (VII).However, methyl 9-octadecynoate (VIII) with excess HNO3 affords methyl 9,10-dioxooctadecanoate (IX), half ester of azelaic acid (X) and methyl 10(11)-oxo-11(10)-nitrooctadecanoate (XI).Structures of these products have been established by their spectral data and elemental analyses.
- Gupta, Archana,Ahmad, F.,Siddiqui, M. S.
-
p. 870 - 872
(2007/10/02)
-