Synthetic Transformations for the Valorization of Fatty Acid Derivatives

Abstract

Oleochemistry is a growing field from the industrial point of view, and one of the basis for a more sustainable chemical production, less dependent of fossil sources. From this point of view, the development of selective and efficient synthetic transformations of triglycerides and fatty acids and esters is an active research field. This short review describes an overview of the most recent advances in the synthetic transformations of fatty acid derivatives into valuable chemicals. 1 Introduction 2 Triglycerides 2.1 Reactions on the ester group and multistep processes 2.2 Epoxidation 2.3 Ozonolysis 2.4 Cross metathesis 3 Reactions on the ester group of fatty acids and esters 3.1 Synthesis of free carboxylic acids 3.2 Synthesis of carboxylic esters 3.3 Reduction to alcohols and aldehydes 3.4 Synthesis of nitrogenated derivatives 4 Oxidation of Unsaturated Fatty acids and esters 4.1 Epoxidation and reactions of epoxides 4.2 Allylic oxidation 4.3 Synthesis of ketoderivatives 4.4 Oxidative cleavage 5 Addition reactions of unsaturated fatty acids and esters 5.1 Hydrogenation and hydroformilation 5.2 Cycloadditions and related reactions 5.3 Addition of carboxylic acids 5.4 Hydroalkylation 5.5 Radical additions 6 Other reactions of unsaturated fatty acids and esters 6.1 Cross metathesis 6.2 Isomerization 7 Conclusion and outlook

Homogeneous and heterogeneous catalytic (dehydrogenative) oxidation of oleochemical 1,2-diols to α-hydroxyketones

“…5 Epoxidized plant oils could also be used for the formation of epoxy resins and their polyolderived analogs for the formation of polyesters and polyurethanes. On the other hand, unsaturated fatty acid derivatives have been intensively studied for the introduction of a wide range of organic functions 6 including aldehyde, 7 epoxide, 8 diol, 9 ketone and diketone, 10 carbonate, 11 among others. 12 Comparatively, there are only few studies related to the α-hydroxyketone function on fatty acid compounds.…”

The Prospering of Macromolecular Materials Based on Plant Oils within the Blooming Field of Polymers from Renewable Resources

“…In fact, oils and fats of vegetable and animal origin make up the greatest proportion of the consumption of renewable raw materials in the chemical industry [23,30]. A widely accepted notion asserts that the fossil-based chemical industry is perfectly consolidated-in terms of technology, investments, and profits-to provide the commodities, fine chemicals, and specialties on which our modern society stands [31]. In order to dispel this "dogma", some obstacles need to be addressed for a wider and more competitive production of chemicals from vegetable oils, and more efficient processes are continuously being designed for this purpose.…”

“…Those reactions mainly consist of tackling the unsaturated bonds, as in the case of epoxidation, hydroformylation, dimerization, thiol-ene coupling, oxidative cleavage (ozonolysis), olefin metathesis, pericyclic reactions, and radical additions, as well as transition-metal catalyzed and Diels-Alder syntheses to aromatic compounds [6,23,32]. Among the chemicals of interest, one finds non-exhaustively, soaps, surfactants, emollients, pesticide formulations, and lubricants [23,[31][32][33][34][35][36]. Rios and coworkers described the synthesis of new lubricant molecules from castor oil by conducting an initial step of esterification of ricinoleic acid with 2-ethylhexanol, followed by epoxidation and ring-opening of the oxirane rings [37].…”

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

“…Starting from 0.50 g of diol 10, according to the literature [32], a loading of 1 mol% for each catalyst was enough to afford complete conversion into the diketone in toluene solution at 100 • C in 5 h. After work-up (quenching with water and extraction), the crude residue was submitted directly to the following step of oxidative cleavage. For the final step of the synthetic procedure, we investigated the Baeyer-Villiger (BV) oxidation of diketone 11, to prepare the corresponding anhydride 12, and hydrolyze it to azelaic (2) and pelargonic acid (3). A wide range of oxidants has been employed for the BV reaction, including mineral and organic peracids.…”

“…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].…”