54105-66-7Relevant academic research and scientific papers
Total syntheses of all tri-oxygenated 16-phytoprostane classes: Via a common precursor constructed by oxidative cyclization and alkyl-alkyl coupling reactions as the key steps
Smr?ek, Jakub,Pohl, Radek,Jahn, Ullrich
, p. 9408 - 9414 (2017)
A unified strategy for the total synthesis of the methyl esters of all phytoprostane (PhytoP) classes bearing two ring-oxygen atoms based on an orthogonally protected common precursor is described. Racemic 16-F1t-, 16-E1-PhytoP and their C-16 epimers, which also occur as racemates in Nature, were successfully obtained. The first total synthesis of very sensitive 16-D1t-PhytoP succeeded, however, it quickly isomerized to more stable, but so far also unknown Δ13-16-D1t-PhytoP, which may serve as a more reliable biomarker for D-type PhytoP. The dioxygenated cyclopentane ring carrying the ω-chain with the oxygen functionality in the 16-position was approached by a radical oxidative cyclization mediated by ferrocenium hexafluorophosphate and TEMPO. The α-chain was introduced by a new copper-catalyzed alkyl-alkyl coupling of a 6-heptenyl Grignard reagent with a functionalized cyclopentylmethyl triflate.
Iron-catalysed allylation-hydrogenation sequences as masked alkyl-alkyl cross-couplings
Bernauer, Josef,Wu, Guojiao,Von Wangelin, Axel
, p. 31217 - 31223 (2019/10/19)
An iron-catalysed allylation of organomagnesium reagents (alkyl, aryl) with simple allyl acetates proceeds under mild conditions (Fe(OAc)2 or Fe(acac)2, Et2O, r.t.) to furnish various alkene and styrene derivatives. Mechanistic studies indicate the operation of a homotopic catalyst. The sequential combination of such iron-catalysed allylation with an iron-catalysed hydrogenation results in overall C(sp3)-C(sp3)-bond formation that constitutes an attractive alternative to challenging direct cross-coupling protocols with alkyl halides.
Insight into forced hydrogen re-arrangement and altered reaction pathways in a protocol for CO2 catalytic processing of oleic acid into C8-C15 alkanes
Xing, Shiyou,Lv, Pengmei,Yuan, Haoran,Yang, Lingmei,Wang, Zhongming,Yuan, Zhenhong,Chen, Yong
supporting information, p. 4157 - 4168 (2017/09/07)
A new vision of using carbon dioxide (CO2) catalytic processing of oleic acid into C8-C15 alkanes over a nano-nickel/zeolite catalyst is reported in this paper. The inherent and essential reasons which make this achievable are clearly resolved by using totally new catalytic reaction pathways of oleic acid transformation in a CO2 atmosphere. The yield of C8-C15 ingredients reaches 73.10 mol% in a CO2 atmosphere, which is much higher than the 49.67 mol% yield obtained in a hydrogen (H2) atmosphere. In the absence of an external H2 source, products which are similar to aviation fuel are generated where aromatization of propene (C3H6) oxidative dehydrogenation (ODH) involving CO2 and propane (C3H8) and hydrogen transfer reactions are found to account for hydrogen liberation in oleic acid and achieve its re-arrangement in the final alkane products. The reaction pathway in the CO2 atmosphere is significantly different from that in the H2 atmosphere, as shown by the presence of 8-heptadecene, γ-stearolactone, and 3-heptadecene as reaction intermediates, as well as a CO formation pathway. Because of the highly dispersed Ni metal center on the zeolite support, H2 spillover is observed in the H2 atmosphere, which inhibits the production of short-chain alkanes and reveals the inherent disadvantage of using H2. The CO2 processing of oleic acid described in this paper will significantly contribute to future CO2 utilization chemistry and provide an economical and promising approach for the production of sustainable alkane products which are similar to aviation fuel.
Process for hydrogenation of carboxylic acids and derivatives to hydrocarbons
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Page/Page column 7-8, (2008/06/13)
A process for hydrogenating a carboxylic acid and/or derivative thereof having a carboxylate group represented by the general formula R1COO-, which process comprises feeding hydrogen and the carboxylic acid and/or derivative thereof to a reactor and maintaining conditions within the reactor such that hydrogen reacts with the carboxylic acid and/or derivative thereof to produce a product stream comprising carbon dioxide, carbon monoxide, methane and hydrocarbons represented by general formulae R1H and R1CH3, characterised in that the molar ratio of R1H : R1CH3 is above a pre-determined value and/or the mole ratio of the sum of carbon dioxide, carbon monoxide and methane to carboxylate groups is above a pre-determined value.
SELECTIVE MIXED COUPLING OF CARBOXYLIC ACIDS (I). - ELECTROLYSIS, THERMOLYSIS AND PHOTOLYSIS OF UNSYMMETRICAL DIACYL PEROXIDES WITH ACYCLIC AND CYCLIC ALKYL GROUPS
Feldhues, Michael,Schaefer, Hans J.
, p. 4195 - 4212 (2007/10/02)
14 unsymmetrical diacyl peroxides (R1CO2-O2CR2 with R1: undecyl; R2: e.g. methyl, propyl, pentyl, nonyl, 2-methylpropyl, 2-propyl, 2-pentyl, cyclopropyl, cyclobutyl, cyclohexyl) are prepared in 85 to 92 percent yield.Square pulse electrolysis of dodecanoyl octanoyl peroxide (1i) affords the unsymmetrical coupling product octadecane (4) in poor yield and selectivity.Thermolysis or photolysis in solution produces preferentially 4, but also considerable amounts of disproportionation products.At -78 deg C the neat peroxides are photolysed selectively to the mixed dimers.With straight chain and β-branched alkyl groups high yields are obtained (63 - 76 percent), with cycloalkyl groups medium yields (42 - 56 percent), and with α-branched diacyl peroxides moderate yields (20 - 33 percent).A comparison of the mixed Kolbe-electrolysis with the low temperature photolysis of the neat peroxide demonstrates the superiority of the latter method in small scale conversion with regard to yield and selectivity.
