591-87-7Relevant articles and documents
Effect of palladium and copper content of zeolite catalysts on the kinetic parameters of the oxidative acetylation of propylene
Kharlamov,Pogorelov,Panov,Yanchevskaya,Minachev
, p. 2424 - 2429 (1989)
1. Using the methods of mathematical planning of an experiment, a kinetic model has been obtained for the oxidative acetylation of propylene to allyl acetate and the effect of the composition of the Pd, Cu/mordenite catalyst on its parameters has been determined. 2. The kinetic parameters (1g k0)0, Q, 1g a0 and E0 correlate strongly and form a gully on the surface of the minimized functional. Regularization of the values of the kinetic parameters was carried out by isolating a subregion of the gully satisfying the Boudart thermodynamic relationships. 3. On varying the Pd and Cu content of the catalyst within the limits 0.1 to 3.0%, the activation energy and the logarithm of the preexponential factor of the rate constant vary over the range 2-11 kcal/mole and 0.255-3.453, respectively.
Heterocyclization, deprotection and isomerization in an intramolecular palladium-catalysed tertiary amine-allyl coupling reaction
Grellier, Mary,Pfeffer, Michel
, p. 2257 - 2258 (1996)
N-Methyl-N-allyl-2-(1-acetoxyalIyl)benzylamine reacts in the presence of tetrakis(triphenylphosphine)palladium to afford a mixture of an isoindole, a 2-benzazepine and allyl acetate; the likely reaction pathway involves a multistep procedure whereby each Pd atom is implicated at least four times, the formation of the isoindole occuring first, followed by an isomerisation to the benzazepine derivative.
Second-Generation meta-Phenolsulfonic Acid-Formaldehyde Resin as a Catalyst for Continuous-Flow Esterification
Hu, Hao,Ota, Hajime,Baek, Heeyoel,Shinohara, Kenta,Mase, Toshiaki,Uozumi, Yasuhiro,Yamada, Yoichi M. A.
supporting information, p. 160 - 163 (2020/01/02)
A second-generation m-phenolsulfonic acid-formaldehyde resin (PAFR II) catalyst was prepared by condensation polymerization of sodium m-phenolsulfonate and paraformaldehyde in an aqueous H2SO4 solution. This reusable, robust acid resin catalyst was improved in both catalytic activity and stability, maintaining the characteristics of the previous generation catalyst (p-phenolsulfonic acid-formaldehyde resin). PAFR II was applied in the batchwise and continuous-flow direct esterification without water removal and provided higher product yields in continuous-flow esterification than any other commercial ion-exchanged acid catalyst tested.
How to Design Selective Ligands for Highly Conserved Binding Sites: A Case Study Using N-Myristoyltransferases as a Model System
Kersten, Christian,Fleischer, Edmond,Kehrein, Josef,Borek, Christoph,Jaenicke, Elmar,Sotriffer, Christoph,Brenk, Ruth
, p. 2095 - 2113 (2019/09/10)
A model system of two related enzymes with conserved binding sites, namely N-myristoyltransferase from two different organisms, was studied to decipher the driving forces that lead to selective inhibition in such cases. Using a combination of computational and experimental tools, two different selectivity-determining features were identified. For some ligands, a change in side-chain flexibility appears to be responsible for selective inhibition. Remarkably, this was observed for residues orienting their side chains away from the ligands. For other ligands, selectivity is caused by interfering with a water molecule that binds more strongly to the off-target than to the target. On the basis of this finding, a virtual screen for selective compounds was conducted, resulting in three hit compounds with the desired selectivity profile. This study delivers a guideline on how to assess selectivity-determining features in proteins with conserved binding sites and to translate this knowledge into the design of selective inhibitors.
Catalytic application of zinc complex of oxygen depleted 1,3-bis(pyrazole)-p-tert-butylcalix[4]arene
Sinha, Anshu Kumar,Vigalok, Arkadi,Rawat, Varun
supporting information, p. 796 - 799 (2019/02/14)
In this paper we have described the synthesis and coordination properties of monometallic Zinc complex of oxygen depleted bis(pyrazole)-p-tert-butylcalix[4]arene ligand. We also present the catalytic activity of the Zinc–bis(pyrazole) complex, in acetylation of alcohols and lactide polymerization.
Coating of polydopamine on polyurethane open cell foams to design soft structured supports for molecular catalysts
Ait Khouya, Ahmed,Mendez Martinez, Miguel L.,Bertani, Philippe,Romero, Thierry,Favier, Damien,Roland, Thierry,Guidal, Valentin,Bellière-Baca, Virginie,Edouard, David,Jierry, Lo?c,Ritleng, Vincent
supporting information, p. 11960 - 11963 (2019/10/11)
Polydopamine-coated polyurethane open cell foams are used as structured supports for molecular catalysts through the covalent anchoring of alkoxysilyl arms by the catechol groups of the mussel-inspired layer. This strong bonding prevents their leaching. No alteration of the mechanical properties of the flexible support is observed after repeated uses of the catalytic materials.
Palladium-Catalyzed Aerobic Homocoupling of Alkynes: Full Mechanistic Characterization of a More Complex Oxidase-Type Behavior
Toledo, Alberto,Funes-Ardoiz, Ignacio,Maseras, Feliu,Albéniz, Ana C.
, p. 7495 - 7506 (2018/07/21)
A combined experimental and computational approach has been used to shed light on the mechanism of the Pd-catalyzed oxidative homocoupling of alkynes using oxygen as the oxidant. Mechanistic understanding is important because of the synthetically relevant direct involvement of oxygen in the oxidative coupling and because of the presence of related processes as undesired side reactions in cross-coupling reactions involving terminal alkynes. A low-ligated [Pd(PPh3)(alkyne)] complex is key in the process, and it can be conveniently generated from allylic palladium(II) complexes in the presence of a base or from Pd(I) allylic dimers as precatalysts. The catalytic coupling occurs by alkyne metalation to give an anionic [Pd(PPh3)(alkynyl)]- complex that is then oxidized by oxygen. The interaction with oxygen occurs only on this electron-rich Pd(0) anionic species and leads to a (κO,κO-peroxo)palladium(II) singlet intermediate that undergoes subsequent protonolysis to give a (κO-hydroperoxo)palladium(II) complex and then hydrogen peroxide. The second alkyne metalation occurs on a Pd(II) derivative to give a bis(alkynyl)palladium(II) complex that evolves to the product by reductive elimination as the product-forming step. This reaction is an oxidase-type process that, in contrast to most Pd-catalyzed oxidative processes, occurs without separation of the substrate transformation and the catalyst oxidation, with these two processes being intertwined and dependent on one another.
METHODS AND COMPOSITIONS FOR TERPENOID SYNTHESIS
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Paragraph 0090; 00140, (2018/04/13)
In one aspect, the disclosure relates to methods for preparation of terpene and terpene-like molecules. In a further aspect, the disclosure relates to the products of the disclosed methods, i.e., terpene and terpene-like molecules prepared using the disclosed methods. Intermediates for the synthesis of a wide variety of terpenoids are γ-allyl Knoevenagel adducts or quasi γ-allyl Knoevenagel adducts are disclosed. In various aspects, methods of preparing terpenoids through these intermediates are disclosed. The methods can comprise α-alkylation of an allylic electrophile followed by ring-closure metathesis to a polycyclic terpenoid structure. In a further aspect, the disclosure pertains to terpenoid frameworks, and compounds prepared via disclosed oxidation and substitution reactions on the disclosed terpenoid frameworks. This abstract is intended as a scanning tool for purposes of searching in the particular art and is not intended to be limiting of the present disclosure.
Assembly of Terpenoid Cores by a Simple, Tunable Strategy
Lahtigui, Ouidad,Emmetiere, Fabien,Zhang, Wei,Jirmo, Liban,Toledo-Roy, Samira,Hershberger, John C.,Macho, Jocelyn M.,Grenning, Alexander J.
, p. 15792 - 15796 (2016/12/16)
Oxygenated, polycyclic terpenoid natural products have important biological activities. Although total synthesis of such terpenes is widely studied, synthetic strategies that allow for controlled placement of oxygen atoms and other functionality remains a challenge. Herein, we present a simple, scalable, and tunable synthetic strategy to assemble terpenoid-like polycycloalkanes from cycloalkanones, malononitrile, and allylic electrophiles, abundantly available reagent classes.
Method for the production of acetic acid allyl ester
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Paragraph 0022; 0023, (2017/08/03)
The invention relates to a method for producing propenyl ethanoate, and mainly aims at solving the problems in the prior art that a catalyst is low in activity and selectivity. Through adopting the method for producing the propenyl ethanoate, propylene, acetic acid, oxygen and water are taken as raw materials, and react with a Pd catalyst in a fixed bed reactor in a contacting manner, so as to generate an effluent containing the propenyl ethanoate; the tubular fixed bed reactor comprises at least two annular baffle plates (7) and at least one inverted conical baffle plate (8); the annular baffle plates (7) and the inverted conical baffle plate (8) are alternately arranged along the axial direction of a reaction tube (2); an upper opening and a lower opening are formed in each annular baffle plate (7); and the projection area of each upper opening in the horizontal direction is smaller than that of each lower opening in the horizontal direction. According to the technical scheme, the problem is well solved; and the method can be applied to industrial production of the propenyl ethanoate employing a propylene gas phase method.