Ultrasound-assisted self-metathesis reactions of monounsaturated fatty acids

Abstract

-An efficient protocol for the self-metathesis of oleic acid, using ruthenium catalysts is described. The self-metathesis reaction under ultrasonic activation allows the conversion of monoenic fatty acids such as oleic acid, elaidic acid and erucic acid into diacids and olefins with very short reaction times in the presence of Grubbs ruthenium catalysts. These yields and selectivity towards the desired products are influenced by the nature of solvents. This study demonstrated that metathesis reaction carried out in DCM or 1-butanol showed promising results, since it produced a variety of products, like n-alkenes and diacids with good yields (45-75%) and high selectivities (75-95%).Keywords: Self-metathesis / long-chain diacids / oleic acid / 1,18-octadec-9-enedioic acid / 1,26-hexacos-13-enedioic acid Résumé -Métathèse activée par les ultrasons : homocouplage d'acides gras monoinsaturés. Un nouveau protocole efficace pour l'homocouplage de l'acide oléique par réaction métathèse utilisant des catalyseurs de ruthénium est décrit dans cet article. La réaction d'homocouplage activée par ultrasons permet d'obtenir avec des temps de réac-tion très faibles, la conversion d'acides gras insaturés tels que l'acide oléique, l'acide élaïdique et l'acide érucique en diacides et oléfines en présence de catalyseurs au ruthénium de Grubbs. Les rendements et la sélectivité des produits obtenus sont influencés par la nature du solvant utilisé. Cette étude a démontré que la réaction de métathèse réalisée dans du dichlorométhane ou du 1-butanol donne des résultats prometteurs : elle permet d'obtenir une grande variété d'alcènes et des diacides à longues chaînes avec de bons rendements (45-75 %) et des sélectivités élevées (75-95 %). Mots clés :Homocouplage / métathèse / diacides à longue chaîne / acide oléique / acide 1,18-octadéc-9-ènedioïque / acide 1,26-hexacos-13-ènedioïque

Phosphomolybdic acid hydrate encapsulated in MIL-53 (Fe): a novel heterogeneous heteropoly acid catalyst for ultrasound-assisted regioselective nitration of phenols

“…27–29 Thus, the development of catalytic reactions under mild conditions using the ultrasound-assisted method as an ideal medium has attracted significant attention in the arena of nitration reactions, because the reactions can be carried out at room temperature, leading to a reduction in the by-products formation and increasing the efficiency of the main products. 30–36…”

Effects of glucose concentration on 1,18-cis-octadec-9-enedioic acid biotransformation efficiency and lipid body formation in Candida tropicalis

“…In this regard, 1,18-octadec-9-enedioic acid (ODA) is a particularly interesting molecule that can be produced by targeted functionalisation of renewable raw materials. Although ODA can be chemically synthesised by self-metathesis of oleic acid catalysed by second-generation Grubbs catalysts, only the trans isomer production has been reported so far (molar yield of approximately 50%) 3 – 5 . Because enzymatic conversion is more selective and can be achieved under reaction conditions milder than current chemical methods, this represents an alternative production route and leads to preservation of the cis configuration.…”

Cross-metathesis of technical grade methyl oleate for the synthesis of bio-based polyesters and polyamides

“…[10][11][12] Moreover, the self-CM of pure methyl oleate (1, Scheme 1), which is the most abundant unsaturated FAME found in natural oil, affords dimethyl octadec-9-enedioate (3, Scheme 1) and internal alkene 5 (Scheme 2a)-both desirable products. 9,[13][14][15][16] Diester 3 is an excellent monomer for synthesizing bio-based and potentially biodegradable polyesters (Scheme 1). A saturated analog of diester 3 was used to obtain long-spaced aliphatic polyesters, [17][18][19] although reports featuring direct use of 3 in polymer synthesis are scarce.…”