Toward new biosilicones: hydrosilylation of fish oil unsaturated fatty acid esters

Abstract

Hydrosilylation of fatty acid methyl esters (FAMEs) were efficiently catalyzed by Speier's and Wilkinson's catalysts in the case of vinylic acid esters, but less efficiently in the case of non-vinylic ones, which gave non-regiospecific additions. In the latter case, initiation by radicals led to regiospecific reactions for oleic esters (C10-silylation). This regiospecificity can be attributed to the higher stability of the C10-silylated adduct and of the corresponding radical intermediate. Only regioselective addition was observed for linoleic esters (C13-silylation % 70%, C10 % 20%, C9 % 10%). Molecular modeling was used to examine the stability of the isomeric products and radicals. The new concept of radical initiation sequence has been successfully applied to FAMEs and then was extended to crude fish oil.

Hydrosilylation of unsaturated fatty acid N‐phenyl amides

“…The EI mass spectrometry study provides useful structural information: first, the fragmentations are in agreement with the C(10)-silylated adduct, which is generally observed with radical initiated hydrosilylation. 7 Moreover, the observation of molecular ion at m/z 527 confirmed both the hydrosilylation of the internal double bond, and the hydrochloration of the amide function. This is corroborated by the IR spectrum, which shows absorption of the carbonyl group at 1704 cm −1 , characteristic of a non-conjugated carbonyl whereas, in the case of amides, this vibration is observed at lower frequencies (around 1660 cm −1 ).…”

“…Unexpectedly, the use of the more reactive trichlorosilane, 7 and of drastic procedures (RIS) 21 followed by treatment by ethanol in the presence of triethylamine yielded cleanly, after elimination of Et 3 N.HCl, the desired triethoxysilylated compound 7 [equation (5)]. …”

“…5,6 In this context, we recently reported the syntheses of organohalosilyl fatty acid methyl esters (FAME) by hydrosilylation of unsaturated FAME (methylundecenoate and 9-methyloleate) for the preparation of ambiphilic polysiloxanes. 7 In contrast, to the best of our knowledge, the hydrosilylation of fatty acid amides has never been developed and remains a stimulating challenge as the fatty acid amides represent an important class of bioactive lipids in human and other mammals. 8 Besides their important properties of biocompatibility, they have also been shown to exhibit unique properties of self-organization.…”

Platinum-Catalysed Hydrosilylation of Unsaturated Fatty Acid Esters

“…[3] A publication of Delpech et al in 2001 focused on the regioselectivity of this reaction. [4] Our group has recently reported about the hydrosilylation of unsaturated fatty acid esters using H 2 PtCl 6 in single-phase and biphasic reaction systems. [5,6] In this article, we present the results of the screening of different Pt(0), Pt(II), and Pt(IV) compounds for the hydrosilylation of fatty acid esters containing terminal as well as internal double bonds.…”

Highly Selective C‐Silylation of Fatty Acid Methyl Esters

“…[10] In this context, we recently reported the syntheses of organohalosilyl FAMEs by hydrosilylation of unsaturated FAMEs (methyl undecenoate and 9-methyl oleate) for the preparation of ambiphilic polysiloxanes. [11] This study has allowed silylation both at the terminal and at various internal positions of the FAMEs. In contrast, the functionalization of the saturated hydrocarbon chain has been poorly developed and remains a stimulating challenge, in particular for saturated aliphatic fatty acids, since they are present in non-negligible amounts in oils and fats.…”