Transition Metals for Conjugation of Polyunsaturated Acids and their Esters

Krompiec, Stanisław; Penczek, R.; Krompiec, Michał; Pluta, Tadeusz; Ignasiak, H.; Kita, Akihisa; Michalik, S.; Matlengiewicz, Marek; Filapek, Michał

doi:10.2174/138527209788452117

Cited by 10 publications

(6 citation statements)

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“…It is however known from the literature that rhodium catalysts allow for the isomerization of polyunsaturated compounds to their conjugated forms. [41][42][43][44] There seemed to be a correlation between the conversions and the proportion of conjugated fatty chains formed during the reaction. Indeed, for oils with a high proportion of polyunsaturated chains (linoleic and linolenic chains) such as soy and sesame oils, the organic phase was strongly colored once the reaction was complete, indicative of catalyst leaching (Table 7, entries 3, 6 and 10).…”

Section: Hydroformylation Of Commercial Oilsmentioning

confidence: 99%

A self-emulsifying catalytic system for the aqueous biphasic hydroformylation of triglycerides

Vanbésien

Sayede

Monflier

et al. 2016

Catal. Sci. Technol.

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Section: Hydroformylation Of Commercial Oilsmentioning

confidence: 99%

A self-emulsifying catalytic system for the aqueous biphasic hydroformylation of triglycerides

Vanbésien

Sayede

Monflier

et al. 2016

Catal. Sci. Technol.

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“…A more detailed discussion of the Ru–H saturation mechanism is provided in the Supporting Information. Second, Ru–H can facilitate isomerization by β-hydride elimination even in the complete absence of H 2 , HD, and D 2 , as shown in Scheme c, and several studies have used the Ru–H catalyst for olefin isomerization via this mechanism. − ,− In addition to isomerization, Tse et al have shown that Ru–H can mediate the H/D exchange between styrene or its derivatives and D 2 O; 85% of the olefinic protons on styrene are replaced by deuterons within an hour at 100 °C. Tse et al explain that H/D exchange occurs by addition of Ru–D to the double bond and subsequent elimination of Ru–H, analogous to the reaction shown in Scheme b with PCP as the substrate.…”

Section: Resultsmentioning

confidence: 99%

“…Carbonylchlorohydridotris(triphenylphosphine)ruthenium(II), denoted Ru–H, is another homogeneous catalyst used for the saturation of unsaturated polymers; like Wilkinson’s catalyst, it is also known to saturate double bonds without causing chain rearrangements such as scission or branching. − However, in contrast to Wilkinson’s catalyst, Ru–H is known to isomerize olefins even in the absence of H 2 , as it bears a hydride ligand that allows a 1,2-insertion to the olefin substrate without needing an oxidative H 2 addition to its metal center. − Consequently, the saturation mechanism is different from that over Wilkinson’s catalyst, where the reducing gas (H 2 or D 2 ) must be added to the metal center prior to forming the σ-metalalkyl intermediate. Gramlich and Hillmyer have prepared polyisoprene containing conjugated double bonds by isomerizing polyisoprene over Ru–H.…”

Section: Introductionmentioning

confidence: 99%

Regularity of Deuteration in Linear Polyethylene Prepared by Saturation of Polycyclopentene over Homogeneous Catalysts

Cho

Pelczer

2021

Macromolecules

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When isotopically labeling polymer chains for small-angle neutron scattering (SANS), it is highly desirable to achieve even intra-and interchain distributions of deuterium (D), such that scattering centers are uniformly placed along and among the chains. A common approach to introduce D is to catalytically saturate an unsaturated precursor polymer with D 2 . Heterogeneous catalysts often induce net H/D exchange between the polymer and D 2 gas, yielding excess D on the polymer which is nonuniformly distributed; however, the homogeneous Wilkinson's catalyst [tris(triphenylphosphine)rhodium(I) chloride] has been shown to yield statistically uniform labeling. Here, 13 C NMR spectroscopy is employed to determine both the deuteration level (DL) and regularity of deuteration in partially deuterated polyethylene (dPE) synthesized by ring-opening metathesis polymerization of cyclopentene followed by deuteration over either Wilkinson's catalyst or an alternative homogeneous catalyst, carbonylchlorohydridotris(triphenylphosphine)ruthenium(II) (Ru−H). Both catalysts produce deuterated methylenes other than the vicinal −CDH−CDH− pair expected from regular deuteration, as a consequence of β-elimination events prior to saturation; under typical saturation conditions, β-elimination is more prevalent with Ru−H. Compared with a DL of 20% expected for ideal regular deuteration, DL values determined by 13 C NMR peak integration are 20.1% for Wilkinson's and 21.9% for Ru−H, indicating significant net H/D exchange over Ru−H. However, SANS from both dPEs shows no angular dependence in the q-range relevant to single-chain dimensions, demonstrating that the deuterium distribution is statistically uniform along and among polymer chains.

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“…Conjugated vegetable oils have found their way into many industrial applications because of their improved drying property. [1][2][3][4][5] In recent years, the physiological functions of the conjugated linoleic acid (CLA) were identified, and studies on the formation of conjugated double bonds in oils or fatty acids have become a major focus of the international chemistry community. Over the past 142 YAN et al few decades, there have been numerous reports on the preparation of conjugated fatty acids and oils.…”

Section: Introductionmentioning

confidence: 99%

Formation of conjugated double bonds in soybean oil with iodine as a catalyst

Yan

Yang

et al. 2016

JSCS

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A method for the iodine-catalyzed formation of conjugated double bonds in soybean oil was developed, and the conjugated product was analyzed by UV, IR and 1 H-NMR. The results indicated that the optimal conditions for the isomerisation included a temperature of 180 °C, a catalyst loading of 0.5 mass % and a reaction time of 3 h. Under these conditions, the concentration of conjugated linoleum acid was 1.51 mol L-1 and the CLNA concentration reached 0.225 mol L-1 with a conversion rate of 99.9 %. The reaction predominantly produced trans-trans, trans-cis and cis-trans isomers. It was also revealed that the isomerisation of linolenic acid was much faster than that of linoleic acid. The method possessed the advantages of a short procedure, a high conversion rate, and no conversion into methyl esters of the raw material and it is an environmentally friendly technology that does not require the use solvents.

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Transition Metals for Conjugation of Polyunsaturated Acids and their Esters

Cited by 10 publications

References 0 publications

A self-emulsifying catalytic system for the aqueous biphasic hydroformylation of triglycerides

A self-emulsifying catalytic system for the aqueous biphasic hydroformylation of triglycerides

Regularity of Deuteration in Linear Polyethylene Prepared by Saturation of Polycyclopentene over Homogeneous Catalysts

Formation of conjugated double bonds in soybean oil with iodine as a catalyst

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