462-18-0Relevant academic research and scientific papers
Long-Range Self-Assembly of an Electron-Deficient Hexaazatrinaphthylene with Out-of-Plane Substituents
Chen, Yi-Ru,Zhang, Yong-Yun,Yeh, Ming-Che,Luo, Ying-Ting,Ong, Chi Wi
, p. 613 - 618 (2019/12/24)
The unprecedented time-dependent long-range supramol-ecular assembly of electron-deficient hexaazatrinaphthylene (HATN) core based on peripheral crowding with three out-of-plane cyclic ketals is reported. The single-crystal X-ray structure of the diethyl derivative provided detailed information as to how four molecules in a repeating unit were packed in order to avoid steric crowding of the out-of-plane cyclic ketal side chain, providing locking and fastening for stabilizing the self-assembled structure. The polarizing optical microscopy (POM) and differential scanning calorimetry (DSC) did not instantaneously show any phase transition upon the cooling process. To our surprise, POM images showed a nucleation of spherulite up to 100 μm after 24 hour later. X-ray diffraction data further confirmed that these soft crystal formed a hexagonal-like crystal. The long-range self-assembly of the new material showed a slight red shift in the UV-vis absorption spectra and further substantiated by computational method.
Highly productive α-alkylation of ketones with alcohols mediated by an Ir-oxalamidato/solid base catalyst system
Maeda, Hironori,Nara, Hideki,Shimizu, Hideo
supporting information, p. 2772 - 2779 (2020/12/29)
An Ir-oxalamidato complex in combination with a solid base (e.g., magnesium aluminometasilicate/Ca(OH)2) significantly improved the catalyst productivity in α-alkylation of methyl ketones with primary alcohols. Optimization through systematic variation of the oxalamidato ligand led to a practical turnover number (TON) of 10 000.40 000.
Deoxygenation of heptanoic acid to hexene over cobalt-based catalysts: A model study for α-olefin production from renewable fatty acid
Choojun, Kittisak,Phichitsurathaworn, Ploynisa,Poo-arporn, Yingyot,Sooknoi, Tawan
, (2020/06/08)
Deoxygenation of heptanoic acid, a model compound, over bimetallic cobalt (Co-Pt, Co-Au, Co-Pd, Co-Ru) supported silica catalysts, was examined for α-olefin production. The catalysts were prepared by conventional impregnation of the metal precursors on silica and characterized by XRF, TEM, H2-TPR, acetic acid-TPD, and XANES. Catalytic testing was performed in a fixed-bed flow reactor under atmospheric H2 pressure. Monometallic cobalt catalysts yielded mainly 1-hexene, but rapid deactivation was observed. Incorporation of 0.5percentwt secondary metal, particularly Pt, increases activity and stability under H2. A relatively higher olefin/paraffin ratio can be obtained from the reaction over 5percentCo+0.5percentPt/SiO2 when compared to that with higher Pt loading. The co-impregnation method offers Co-Pt catalysts with stability higher than that prepared by the sequential impregnation method. Over cobalt-based catalysts, the deoxygenation is proposed to proceed via reduction of heptanoic acid to heptanal that is an intermediate for decarbonylation to hexene; while other side reactions are suppressed.
Dehydrogenative Coupling of Benzylic and Aldehydic C-H Bonds
Ishida, Naoki,Kawasaki, Tairin,Murakami, Masahiro
supporting information, p. 3366 - 3370 (2020/03/06)
A photoinduced dehydrogenative coupling reaction between benzylic and aldehydic C-H bonds is reported. When a solution of an alkylbenzene and an aldehyde in ethyl acetate is irradiated with visible light in the presence of iridium and nickel catalysts, a coupled α-aryl ketone is formed with evolution of dihydrogen. An analogous C-C bond forming reaction occurs between a C-H bond next to the nitrogen of an N-methylamide and an aldehydic C-H bond to produce an α-amino ketone. These reactions provide a straightforward pathway from readily available materials leading to valued structural motifs of pharmacological relevance.
IONIZABLE CATIONIC LIPID FOR RNA DELIVERY
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, (2018/07/04)
What is described is a compound of formula I consisting of a compound in which R1 is a branched chain alkyl consisting of 10 to 31 carbons; R2 is a linear alkyl, alkenyl, or alkynyl consisting of 2 to 20 carbons; L1 and L2 are the same or different, each a linear alkylene of 1 to 20 carbons or a linear alkenylene of 2 to 20 carbons; X1 is S or O; R3 is a linear or branched alkylene consisting of 1 to 6 carbons; and R4 and R5 are the same or different, each a hydrogen or a linear or branched alkyl consisting of 1 to 6 carbons; or a pharmaceutically acceptable salt thereof.
IONIZABLE CATIONIC LIPID FOR RNA DELIVERY
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, (2018/07/05)
What is described is a compound of formula I consisting of a compound in which R1 is a branched chain alkyl consisting of 10 to 31 carbons;R2 is a linear alkyl, alkenyl, or alkynyl consisting of 2 to 20 carbons, or a branched chain alkyl consisting of 10 to 31 carbons;L1 and L2 are the same or different, each a linear alkane of 1 to 20 carbons or a linear alkene of 2 to 20 carbons;X1 is S or O;R3 is a linear or branched alkylene consisting of 1 to 6 carbons; andR4 and R5 are the same or different, each a hydrogen or a linear or branched alkyl consisting of 1 to 6 carbons; or a pharmaceutically acceptable salt thereof.
Chelation-Assisted C-H and C-C Bond Activation of Allylic Alcohols by a Rh(I) Catalyst under Microwave Irradiation
Lee, Chang-Hee,Jun, Chul-Ho
, p. 736 - 741 (2017/11/27)
Chelation-assisted Rh(I)-catalyzed ketone synthesis from allylic alcohols and alkenes through C-H and C-C bond activations under microwave irradiation was developed. Aldimine is formed via olefin isomerization of allyl alcohol under Rh(I) catalysis and condensation with 2-amino-3-picoline, followed by continuous C-H and C-C bond activations to produce a dialkyl ketone. The addition of piperidine accelerates the reaction rate by promoting aldimine formation under microwave conditions.
Cerium oxide as a catalyst for the ketonization of aldehydes: Mechanistic insights and a convenient way to alkanes without the consumption of external hydrogen
Orozco, Lina M.,Renz, Michael,Corma, Avelino
supporting information, p. 1555 - 1569 (2017/05/10)
The ketonization of aldehydes joins two molecules, with n carbon atoms each, to a ketone with 2n - 1 carbon atoms. When employing cerium oxide as a catalyst with nano-sized crystals (15 nm) the ketone can be obtained in almost 80% yield. In addition, other ketones are observed so that the total ketone selectivity reached almost 90%. Water is consumed during the reaction when the aldehyde is oxidized to the corresponding carboxylic acid, which is established as a reaction intermediate, co-producing hydrogen. Consequently, water has to be co-fed in the reaction to enhance the reaction rate and to improve the catalyst stability with time on stream. In contrast to zirconium oxide which possesses catalytic activity for the aldol condensation liberating water, with cerium oxide water is not abundant on the surface and the reaction kinetics show that the reaction rate depends on the concentration of the water in the gas-phase, in addition to the dependence on the gas-phase concentration of the aldehyde. The liberated hydrogen can be consumed in the hydrodeoxygenation of the ketone product. Doing so, when starting from heptanal, a biomass derived aldehyde, an alkane mixture was obtained with almost 90% diesel content. For the whole cascade reaction with five single steps no reagents are necessary and the only by-product is one molecule of innocuous carbon dioxide (related to two molecules of aldehyde). This shows that cerium oxide possesses a big potential to convert biomass derived aldehydes into biofuels in a very sustainable way.
Carbon–Carbon Bond Formation and Hydrogen Production in the Ketonization of Aldehydes
Orozco, Lina M.,Renz, Michael,Corma, Avelino
, p. 2430 - 2442 (2016/10/24)
Aldehydes possess relatively high chemical energy, which is the driving force for disproportionation reactions such as Cannizzaro and Tishchenko reactions. Generally, this energy is wasted if aldehydes are transformed into carboxylic acids with a sacrificial oxidant. Here, we describe a cascade reaction in which the surplus energy of the transformation is liberated as molecular hydrogen for the oxidation of heptanal to heptanoic acid by water, and the carboxylic acid is transformed into potentially industrially relevant symmetrical ketones by ketonic decarboxylation. The cascade reaction is catalyzed by monoclinic zirconium oxide (m-ZrO2). The reaction mechanism has been studied through cross-coupling experiments between different aldehydes and acids, and the final symmetrical ketones are formed by a reaction pathway that involves the previously formed carboxylic acids. Isotopic studies indicate that the carboxylic acid can be formed by a hydride shift from the adsorbed aldehyde on the metal oxide surface in the absence of noble metals.
Decarbonylation of heptanoic acid over carbon-supported platinum nanoparticles
Lopez-Ruiz, Juan A.,Davis, Robert J.
, p. 683 - 694 (2014/02/14)
The decarbonylation and decarboxylation of heptanoic acid over carbon-supported Pt nanoparticles were studied in a continuous flow fixed bed reactor at 573 K and 37 bar for liquid-phase operation and 1 bar for gas-phase operation. Under liquid-phase conditions, the TOF over Pt supported on Norit carbon was 0.0052 s-1 and independent of Pt loading. At very low conversions, approaching zero, the product selectivity was consistent with decarbonylation as the primary reaction, producing mostly hexenes and CO. As conversion increased from 1% to 5% at 37 bar, substantial amounts of hexane and CO2 were observed, presumably from secondary side reactions such as water-gas shift (WGS) and hydrogenation instead of direct decarboxylation. The terminal olefin was observed with high selectivity (57%) only during gas-phase operation (1 bar) which facilitated transport of the olefin away from the Pt that also catalyzed double bond isomerization. Some sintering of the Pt metal particles during reaction of heptanoic acid was observed by X-ray diffraction analysis of the spent catalyst. Catalyst regeneration studies were performed over spent catalyst but they failed to restore any catalytic activity.
