130879-97-9Relevant articles and documents
Silicate anion-stabilized layered magnesium-aluminium hydrotalcite
Baskaran, Thangaraj,Kumaravel, Raju,Christopher, Jayaraj,Sakthivel, Ayyamperumal
, p. 16392 - 16398 (2013)
Layered magnesium-aluminum hydrotalcite (HT) were completely intercalated and stabilized with silicate anions. The silicate anion-stabilized HT retained the layered structure and possessed a high surface area of 530-540 m2 g-1 with needle-like particles 60 nm × 4 nm in dimension. The findings of FT-IR, powder XRD, TGA, DSC and 29Si MAS-NMR revealed that silicate anions were intercalated and coated on the surface of layered HTs with the formation of a solid solution of magnesium silicate and HT. The resultant silicate-anion-intercalated materials are found to be promising catalysts for the synthesis of 1-phenoxy-2-propanol using phenol with propylene oxide. The Royal Society of Chemistry 2013.
Water-resistant solid Lewis acid catalysts: Meerwein-Ponndorf-Verley and Oppenauer reactions catalyzed by tin-beta zeolite
Corma, Avelino,Domine, Marcelo E.,Valencia, Susana
, p. 294 - 304 (2003)
The catalytic activity of Sn-beta zeolite in the Meerwein-Pondorf-Verley reduction of carbonyl compounds with secondary alcohols as reductants and Oppenauer oxidation of alcohols were performed with quantitative yields to the corresponding product. The catalyst had an excellent activity and selectivity even after four catalytic recycles, and good stereoselectivities to the thermodynamic less favorable cis-alcohol isomer when alkyl-cyclohexanones were used as substrates. A prochiral ketone was reduced within an enantiomeric excess close to 50% when using a chiral alcohol as the reducing reactant. IR studies using cyclohexanone as probe molecule over beta zeolites showed that the more specific Lewis acid sites in the framework of Sn-beta were responsible for its better catalytic activity with respect to Ti- or Al-beta. The order of hydrophobicity of the samples was Ti-beta > Sn-beta > Al-beta. Ti-beta and Sn-beta retained a higher percentage of catalytic activity when water was present in the reaction media. Even with ～ 4 wt % of H2O (0.2 g) in the media, Sn-beta yielded a higher turnover number than Ti- or Al-beta when working in the absence of water.
Resolution of 1-phenoxy-, 1-phenylmethoxy- and 1-(2-phenylethoxy)-2-propanol and their butanoates by hydrolysis with lipase B from Candida antarctica
Hoff, Bard H.,Waagen, Viggo,Anthonsen, Thorleif
, p. 3181 - 3186 (1996)
Resolutions of butanoic esters of 1-phenoxy-2-propanol, 1-phenylmethoxy-2-propanol and 1-(2-phenylethoxy)-2-propanol have been studied with four different lipases as catalysts. Using lipase B from Candida antarctica very high enantiomer ratios were obtained. These substrate-lipase pairs represent an excellent way of getting enantiomerically pure protected 1,2-propanediols in high chemical yield. Copyright (C) Elsevier Science Ltd.
A SIMPLE METHOD FOR CALCULATING ENANTIOMER RATIO AND EQUILIBRIUM CONSTANTS IN BIOCATALYTIC RESOLUTIONS
Anthonsen, Henrik W.,Hoff, Bard Helge,Anthonsen, Thorleif
, p. 3015 - 3022 (1995)
A computer programme for determination of equilibrium constant (K) and enantiomer ratio (E) in biocatalytic resolutions has been developed.The programme utilises experimental data, ees and eep measured at more than one conversion, and determines both K and E no matter whether the reaction is irreversible (K=0) or reversible (K>0).An estimation of errors in the calculations indicates that errors in E does not show a Gaussian distribution, while errors in K does.The usefulness of the programme has been tested in a lipase-catalysed transesterification of 1-phenoxy-2-propanol at various concentrations of acyl donor, with different solvents and at different water activities.
Inducing high activity of a thermophilic enzyme at ambient temperatures by directed evolution
Li, Guangyue,Maria-Solano, Miguel A.,Romero-Rivera, Adrian,Osuna, Sílvia,Reetz, Manfred T.
, p. 9454 - 9457 (2017)
The long-standing problem of achieving high activity of a thermophilic enzyme at low temperatures and short reaction times with little tradeoff in thermostability has been solved by directed evolution, an alcohol dehydrogenase found in hot springs serving as the catalyst in enantioselective ketone reductions.
Improved Biocatalytic Activity of the Debaryomyces Species in Seawater
Andreu, Cecilia,del Olmo, Marcel?lí
, p. 3085 - 3092 (2019)
Biocatalysis is an environmentally friendly strategy widely used in the chemical and pharmaceutical industries. One of its approaches consists in utilizing whole cells, which usually involves the consumption of large quantities of water. Oceans cover a large part of the Earth's surface, and constitute an important reservoir that can be used as an alternative to freshwater in chemical reactors. This work analyzed the behavior of several yeast halotolerant species belonging to genera Debaryomyces and Schwanniomyces in both freshwater and seawater. It concluded that these microorganisms were more resistant to organic solvents/compounds in the second medium. Their metabolic activity was also greater, which made the reduction reaction of several prochiral ketones more effective. Besides, yeasts cells displayed better performance in subsequent recycling steps, which could help reduce the costs of the process.
Regiodivergent Reductive Opening of Epoxides by Catalytic Hydrogenation Promoted by a (Cyclopentadienone)iron Complex
De Vries, Johannes G.,Gandini, Tommaso,Gennari, Cesare,Jiao, Haijun,Pignataro, Luca,Stadler, Bernhard M.,Tadiello, Laura,Tin, Sergey
, p. 235 - 246 (2022/01/03)
The reductive opening of epoxides represents an attractive method for the synthesis of alcohols, but its potential application is limited by the use of stoichiometric amounts of metal hydride reducing agents (e.g., LiAlH4). For this reason, the corresponding homogeneous catalytic version with H2 is receiving increasing attention. However, investigation of this alternative has just begun, and several issues are still present, such as the use of noble metals/expensive ligands, high catalytic loading, and poor regioselectivity. Herein, we describe the use of a cheap and easy-To-handle (cyclopentadienone)iron complex (1a), previously developed by some of us, as a precatalyst for the reductive opening of epoxides with H2. While aryl epoxides smoothly reacted to afford linear alcohols, aliphatic epoxides turned out to be particularly challenging, requiring the presence of a Lewis acid cocatalyst. Remarkably, we found that it is possible to steer the regioselectivity with a careful choice of Lewis acid. A series of deuterium labeling and computational studies were run to investigate the reaction mechanism, which seems to involve more than a single pathway.
Primary Alcohols via Nickel Pentacarboxycyclopentadienyl Diamide Catalyzed Hydrosilylation of Terminal Epoxides
Lambert, Tristan H.,Steiniger, Keri A.
supporting information, p. 8013 - 8017 (2021/10/25)
The efficient and regioselective hydrosilylation of epoxides co-catalyzed by a pentacarboxycyclopentadienyl (PCCP) diamide nickel complex and Lewis acid is reported. This method allows for the reductive opening of terminal, monosubstituted epoxides to form unbranched, primary alcohols. A range of substrates including both terminal and nonterminal epoxides are shown to work, and a mechanistic rationale is provided. This work represents the first use of a PCCP derivative as a ligand for transition-metal catalysis.
CATALYST FOR PREPARING PROPYLENE GLYCOL PHENYL ETHER AND METHOD FOR SYNTHESIZING PROPYLENE GLYCOL PHENYL ETHER
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Paragraph 0022-0049, (2020/06/08)
Disclosed is a method for preparing propylene glycol phenyl ether, comprising carrying out a polymerization reaction of phenol and a propylene oxide in the presence of a quaternary phosphonium salt compound as a catalyst. Preferably, the method comprises mixing phenol and a quaternary phosphonium salt compound, and then adding propylene oxide under oxygen-free conditions, wherein the phenol is polymerized with the propylene oxide to produce the propylene glycol phenyl ether. The propylene glycol phenyl ether thus prepared has few impurities and contains no metal ions, such as potassium and sodium, and does not require subsequent operations to remove metal ions and perform rectification separation, thereby reducing the costs and allowing same to be directly applied to high-standard industrial production.
Selective Cross-Dehydrogenative C(sp3)-H Arylation with Arenes
Hao, Hong-Yan,Mao, Yang-Jie,Xu, Zhen-Yuan,Lou, Shao-Jie,Xu, Dan-Qian
supporting information, p. 2396 - 2402 (2020/03/13)
Selective C(sp3)-C(sp2) bond construction is of central interest in chemical synthesis. Despite the success of classic cross-coupling reactions, the cross-dehydrogenative coupling between inert C(sp3)-H and C(sp2)-H bonds represents an attractive alternative toward new C(sp3)-C(sp2) bonds. Herein, we establish a selective inter-and intramolecular C(sp3)-H arylation of alcohols with nondirected arenes that thereby provides a general pathway to access a wide range of β-arylated alcohols, including tetrahydronaphthalen-2-ols and benzopyran-3-ols, with high to excellent chemo-and regioselectivity.
