15790-87-1Relevant academic research and scientific papers
Nylon Intermediates from Bio-Based Levulinic Acid
Marckwordt, Annemarie,El Ouahabi, Fatima,Amani, Hadis,Tin, Sergey,Kalevaru, Narayana V.,Kamer, Paul C. J.,Wohlrab, Sebastian,de Vries, Johannes G.
, p. 3486 - 3490 (2019)
Use of ZrO2/SiO2 as a solid acid catalyst in the ring-opening of biobased γ-valerolactone with methanol in the gas phase leads to mixtures of methyl 2-, 3-, and 4-pentenoate (MP) in over 95 % selectivity, containing a surprising 81 % of M4P. This process allows the application of a selective hydroformylation to this mixture to convert M4P into methyl 5-formyl-valerate (M5FV) with 90 % selectivity. The other isomers remain unreacted. Reductive amination of M5FV and ring-closure to ?-caprolactam in excellent yield had been reported before. The remaining mixture of 2- and 3-MP was subjected to an isomerising methoxycarbonylation to dimethyl adipate in 91 % yield.
Towards 'bio-based' Nylon: Conversion of γ-valerolactone to methyl pentenoate under catalytic distillation conditions
Lange, Jean-Paul,Vestering, Jan Z.,Haan, Rene J.
, p. 3488 - 3490 (2007)
Methyl pentenoate, a promising Nylon intermediate, is produced in >95% yield via the transesterification of γ-valerolactone, a bio-based intermediate, under catalytic distillation conditions. The Royal Society of Chemistry.
Ionic-liquid-catalyzed efficient transformation of γ-valerolactone to methyl 3-pentenoate under mild conditions
Zeng, Fan-Xin,Liu, Hai-Feng,Deng, Li,Liao, Bing,Pang, Hao,Guo, Qing-Xiang
, p. 600 - 603 (2013)
Green nylons! Acidic ionic-liquid catalysis for the transformation of g-valerolactone into methyl 3-pentenoate (M3P) is shown to be performed efficiently under mild conditions. M3P is obtained selectively from a reaction at 1708C for 3.5 h in the presence of an acidic ionic liquid that has a low vapor pressure, high thermal stability, and excellent catalytic performance. A possible reaction pathway for this conversion is also presented.
Ir-Catalyzed Remote Functionalization by the Combination of Deconjugative Chain-Walking and C-H Activation Using a Transient Directing Group
Tang, King Hung Nigel,Uchida, Kanako,Nishihara, Kazuki,Ito, Mamoru,Shibata, Takanori
supporting information, p. 1313 - 1317 (2022/02/23)
An Ir-catalyzed reaction of N-benzylideneanilines with functionalized alkenes such as α,β-unsaturated esters gave ortho-substituted benzaldehyde derivatives with a functional group at the remote position after acidic treatment. The present transformation
OLIGONUCLEOTIDE COMPOSITIONS AND METHODS THEREOF
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Paragraph 00806; 00808, (2021/11/26)
The present disclosure provides modified oligonucleotides and compositions and methods thereof. In some embodiments, provided technologies comprise modified sugars and/or modified internucleotidic linkages. In some embodiments, the present disclosure provides technologies for preparing modified oligonucleotides. In some embodiments, the present disclosure provides chirally controlled oligonucleotide compositions and methods for their preparation and uses.
Directing Selectivity to Aldehydes, Alcohols, or Esters with Diphobane Ligands in Pd-Catalyzed Alkene Carbonylations
Aitipamula, Srinivasulu,Britovsek, George J. P.,Nobbs, James D.,Tay, Dillon W. P.,Van Meurs, Martin
, p. 1914 - 1925 (2021/06/28)
Phenylene-bridged diphobane ligands with different substituents (CF3, H, OMe, (OMe)2, tBu) have been synthesized and applied as ligands in palladium-catalyzed carbonylation reactions of various alkenes. The performance of these ligands in terms of selectivity in hydroformylation versus alkoxycarbonylation has been studied using 1-hexene, 1-octene, and methyl pentenoates as substrates, and the results have been compared with the ethylene-bridged diphobane ligand (BCOPE). Hydroformylation of 1-octene in the protic solvent 2-ethyl hexanol results in a competition between hydroformylation and alkoxycarbonylation, whereby the phenylene-bridged ligands, in particular, the trifluoromethylphenylene-bridged diphobane L1 with an electron-withdrawing substituent, lead to ester products via alkoxycarbonylation, whereas BCOPE gives predominantly alcohol products (n-nonanol and isomers) via reductive hydroformylation. The preference of BCOPE for reductive hydroformylation is also seen in the hydroformylation of 1-hexene in diglyme as the solvent, producing heptanol as the major product, whereas phenylene-bridged ligands show much lower activities in this case. The phenylene-bridged ligands show excellent performance in the methoxycarbonylation of 1-octene to methyl nonanoate, significantly better than BCOPE, the opposite trend seen in hydroformylation activity with these ligands. Studies on the hydroformylation of functionalized alkenes such as 4-methyl pentenoate with phenylene-bridged ligands versus BCOPE showed that also in this case, BCOPE directs product selectivity toward alcohols, while phenylene-bridge diphobane L2 favors aldehyde formation. In addition to ligand effects, product selectivities are also determined by the nature and the amount of the acid cocatalyst used, which can affect substrate and aldehyde hydrogenation as well as double bond isomerization.
Modulation of N^N′-bidentate chelating pyridyl-pyridylidene amide ligands offers mechanistic insights into Pd-catalysed ethylene/methyl acrylate copolymerisation
ó Máille, Gearóid M.,Albrecht, Martin,Dall'Anese, Anna,Grossenbacher, Philipp,Milani, Barbara,Montini, Tiziano
, p. 6133 - 6145 (2021/05/19)
The efficient copolymerisation of functionalised olefins with alkenes continues to offer considerable challenges to catalyst design. Based on recent work using palladium complexes containing a dissymmetric N^N′-bidentate pyridyl-PYA ligand (PYA = pyridylidene amide), which showed a high propensity to insert methyl acrylate, we have here modified this catalyst structure by inserting shielding groups either into the pyridyl fragment, or the PYA unit, or both to avoid fast β-hydrogen elimination. While a phenyl substituent at the pyridyl side impedes catalytic activity completely and leads to an off-cycle cyclometallation, the introduction of an ortho-methyl group on the PYA side of the N^N′-ligand was more prolific and doubled the catalytic productivity. Mechanistic investigations with this ligand system indicated the stabilisation of a 4-membered metallacycle intermediate at room temperature, which has previously been postulated and detected only at 173 K, but never observed at ambient temperature so far. This intermediate was characterised by solution NMR spectroscopy and rationalises, in part, the formation of α,β-unsaturated esters under catalytic conditions, thus providing useful principles for optimised catalyst design.
Selecting double bond positions with a single cation-responsive iridium olefin isomerization catalyst
Camp, Andrew M.,Kita, Matthew R.,Blackburn, P. Thomas,Dodge, Henry M.,Chen, Chun-Hsing,Miller, Alexander J.M.
supporting information, p. 2792 - 2800 (2021/03/01)
The catalytic transposition of double bonds holds promise as an ideal route to alkenes of value as fragrances, commodity chemicals, and pharmaceuticals; yet, selective access to specific isomers is a challenge, normally requiring independent development of different catalysts for different products. In this work, a single cation-responsive iridium catalyst selectively produces either of two different internal alkene isomers. In the absence of salts, a single positional isomerization of 1-butene derivatives furnishes 2-alkenes with exceptional regioselectivity and stereoselectivity. The same catalyst, in the presence of Na+, mediates two positional isomerizations to produce 3-alkenes. The synthesis of new iridium pincer-crown ether catalysts based on an aza-18-crown-6 ether proved instrumental in achieving cation-controlled selectivity. Experimental and computational studies guided the development of a mechanistic model that explains the observed selectivity for various functionalized 1-butenes, providing insight into strategies for catalyst development based on noncovalent modifications.
Regioselective Isomerization of Terminal Alkenes Catalyzed by a PC(sp3)Pincer Complex with a Hemilabile Pendant Arm
De-Botton, Sophie,Filippov, D.Sc. Oleg A.,Shubina, Elena S.,Belkova, Natalia V.,Gelman, Dmitri
, p. 5959 - 5965 (2020/10/15)
We describe an efficient protocol for the regioselective isomerization of terminal alkenes employing a previously described bifunctional Ir-based PC(sp3)complex (4) possessing a hemilabile sidearm. The isomerization, catalyzed by 4, results in a one-step shift of the double bond in good to excellent selectivity, and good yield. Our mechanistic studies revealed that the reaction is driven by the stepwise migratory insertion of Ir?H species into the terminal double bond/β-H elimination events. However, the selectivity of the reaction is controlled by dissociation of the hemilabile sidearm, which acts as a selector, favoring less sterically hindered substrates such as terminal alkenes; importantly, it prevents recombination and further isomerization of the internal ones.
METHOD FOR PRODUCING PENTENOIC ACID ESTER
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Paragraph 0041; 0042; 0043; 0048; 0051; 0052, (2019/01/19)
PROBLEM TO BE SOLVED: To provide a production method capable of obtaining a pentenoic acid ester in high yield even without using a large amount of alcohol while suppressing by-production of an ether. SOLUTION: There is provided a method for producing a pentenoic acid ester, which comprises a step of synthesizing a pentenoic acid ester containing at least one selected from the group consisting of formulas (2), (3) and (4) by bringing γ-valerolactone and an alcohol of the formula (1) into contact with each other in the presence of a catalyst containing X type zeolite. [In the formula (1), R represents an alkyl group having 1 to 6 carbon atoms. In the formulas (2), (3) and (4), R represents an alkyl group having 1 to 6 carbon atoms]. SELECTED DRAWING: None COPYRIGHT: (C)2019,JPOandINPIT
