Olefin metathesis of fatty acids and vegetable oils

Abstract

The article reviews various olefin metathesis reactions namely self-metathesis (SM), crossmetathesis (CM), acyclic diene metathesis (ADMET) polymerization, ring closing metathesis (RCM) and ring opening metathesis (ROM) reactions for the synthesis of a variety of platform chemicals with potential industrial applications from vegetable oils and fatty acids. Different fatty acids employed for various metathesis reactions were oleic, linoleic, linolenic, eicosenoic, erucic, petroselinic, sterculic, undecenoic and ricinoleic acids, while vegetable oils used were Helianthus (sunflower), Brassica napus (rapeseed), Glycine max (soybean), Hevea brasiliensis (rubber), Butea monosperma (palash), Nicotiana tabacum (tobacco) and Sterculia foetida (jangli badam). Even though Grubbs' catalysts were employed for most of the reactions, other catalysts such as rhenium, molybdenum and tungsten based have also been used for selective reactions of vegetable oils and fatty acids. The article reviews some of the mechanistic pathways involved in the generation of unusual intermediates from fatty acids and triglycerides.

Synthesis and Characterization of Partially Renewable Oleic Acid-Based Ionomers for Proton Exchange Membranes

“…1 H-NMR, 13 C-NMR, and 19 F-NMR spectra were recorded on a Bruker Avance III HD at 400, 100, and 376 MHz, respectively, in DMSO-d 6 . Tetramethylsilane (TMS) and hexafluorobenzene (HFB) were used as internal standards.…”

“…These renewable polymers have to be produced at low cost, with few steps for their synthesis and should also have properties comparable with their counterparts obtained from petrochemical compounds in order to be used on a commercial scale [ 11 , 12 ]. In this regard, vegetable oils containing unsaturated fatty acids are promising, cheap, and renewable sources to generate a huge number of oleochemicals that can be employed for the synthesis of high-value compounds in a sustainable manner [ 13 , 14 ]. Particularly, long-chain vegetable oils are the most important, with oleic acid being one of the most abundant fatty acids in most vegetable oils [ 9 , 14 ].…”

“…It is well known that olefin metathesis is a powerful and versatile tool in the petrochemical industry for various processes; however, it also has an excellent area of application in the oleochemical industry [ 14 ]. This technique provides a convenient and selective route to form dicarboxylic acids, which are basic components of great value for the current chemical industry and are used in the production of a vast variety of chemical products, among them plastics such as polyesters and polyamides [ 13 , 14 , 15 , 16 ]. In this context, the synthesis of polyesters derived from vanillin and fatty acid derivatives have been reported [ 17 ]; likewise, the synthesis of polyamides obtained from 1,9-azelaic acid has also been accomplished successfully [ 18 ].…”

“…In this regard, vegetable oils containing unsaturated fatty acids are promising, cheap, and renewable sources to generate a huge number of oleochemicals that can be employed for the synthesis of high-value compounds in a sustainable manner [13,14]. Particularly, long-chain vegetable oils are the most important, with oleic acid being one of the most abundant fatty acids in most vegetable oils [9,14].…”

“…Then, the oleic diacid obtained was subjected to polycondensation reactions with two aromatic diamines, 4,4 -(hexafluoroisopropylidene)bis(pphenyleneoxy)dianiline and 4,4 -diamino-2,2 -stilbenedisulfonic acid, as comonomers for the synthesis of a series of novel aromatic-aliphatic polyamides with increasing degree of sulfonation (DS). The polymer chemical structures were characterized by Fourier transform infrared (FTIR) and nuclear magnetic resonance ( 1 H, 13 C and 19 F NMR) spectroscopy. Finally, the proton conductivity in membranes of these partially renewable ionomers was determined by electrochemical impedance spectroscopy (EIS).…”