Oxidative Cleavage of Fatty Acid Derivatives for Monomer Synthesis

Abstract

Oxidative cleavage of fatty acids and fatty acid derivatives is a practical way to obtain bifunctional molecules that can be used in polycondensation reactions. Diacids, hydroxyacids, and amino acids can then be used to produce polyesters or polyamides and also a large range of other products, such as lubricants and plasticizers. Ozonolysis has long been the sole industrial process for oxidative cleavage, but recently, routes using hydrogen peroxide as a clean oxidant have regained interest. Hydrogen peroxide is easier to use, but the kinetics of the catalyzed reactions are still slow. Although several catalytic systems have been described in the literature, tungsten-based catalysts are still the preferred choices. Different catalysts can trigger different mechanisms, such as a radical mechanism instead of a catalytic reaction. In addition, some side products and co-products often disregarded in the literature, such as shorted cleavage products, indicate the presence of side reactions that affect the quality of the final products. The oxidative cleavages in continuous and batch processes have significant differences, which are discussed with an illustration of our understanding of the process used by Matrica S.p.A.

Conversion of Oleic Acid into Azelaic and Pelargonic Acid by a Chemo-Enzymatic Route

“…The latter are then submitted to reactions involving either the carboxylic group (to afford soaps, esters, amides, amines, and alcohols) or the reduction/oxidation of the C=C double bonds, if present. Among these procedures developed to obtain fine chemicals, the oxidative cleavage of unsaturated fatty acids for the production of dicarboxylic acids, hydroxy acids, and amino acids has received great attention in the last decade [2][3][4]. Until recently, only two dicarboxylic acids prepared from oleochemicals have been commercialized, i.e., sebacic acid (1), obtained by the alkaline cleavage of castor oil [5], and azelaic acid (2), which is produced together with pelargonic acid (3) by ozonolysis of oleic acid (4) (Figure 1) [6].…”

“…acid (2), which is produced together with pelargonic acid (3) by ozonolysis of oleic acid (4) (Figure 1) [6]. Sebacic and azelaic acid are extensively employed in the synthesis of new generation biodegradable copolymers [7].…”

“…Oxidative Cleavage of 9,10-Dioxostearic Acid(11) to Azelaic(2) and Pelargonic Acid(3)A mixture of crude dioxo derivative 11 (1.75 g, 75% purity, estimated content of compound 11 4.21 mmol) and 35% H 2 O 2 w/w (579 µL, 6.73 mmol) in toluene (35 mL) was stirred at 30 • C for 3 h. A saturated solution of NaHSO 3 (750 µL) was added, followed by the addition of H 2 SO 4 2 M till pH = 2. The reaction mixture was then extracted with ethyl acetate.…”

Aerobic Oxidative Cleavage of Vicinal Diol Fatty Esters by a Supported Ruthenium Hydroxide Catalyst

“…Oxidation methods are widely used to transform unsaturated fatty acids into useful building blocks for the synthesis of monomers that have countless applications in the textile and automobile industries. 4 The transformation of alkenes through an oxidation process also leads to the production of a large panel of compounds (epoxides, diols, aldehydes, etc…). 1,5 The products of oxidative cleavage of oleic acid 1a are pelargonic 2 and azelaic acids 3 ( Figure 1).…”

Selective dihydroxylation of methyl oleate to methyl-9,10-dihydroxystearate in the presence of a recyclable tungsten based catalyst and hydrogen peroxide

“…28,29 The use of an excess of H2O2 is problematic on large scales due to safety considerations. 30 In the case of low concentrated solution of H2O2, the sheer volume of the aqueous reagents required can be detrimental to the reaction and phase transfer agent are required. The synthesis of diols from FAME require the control the selectivity and a concentrated solution of H2O2.…”