3395-88-8Relevant articles and documents
High Throughput Screening with SAMDI Mass Spectrometry for Directed Evolution
Pluchinsky, Adam J.,Wackelin, Daniel J.,Huang, Xiongyi,Arnold, Frances H.,Mrksich, Milan
, p. 19804 - 19808 (2020)
Advances in directed evolution have led to an exploration of new and important chemical transformations; however, many of these efforts still rely on the use of low-throughput chromatography-based screening methods. We present a high-throughput strategy for screening libraries of enzyme variants for improved activity. Unpurified reaction products are immobilized to a self-assembled monolayer and analyzed by mass spectrometry, allowing for direct evaluation of thousands of variants in under an hour. The method was demonstrated with libraries of randomly mutated cytochrome P411 variants to identify improved catalysts for C-H alkylation. The technique may be tailored to evolve enzymatic activity for a variety of transformations where higher throughput is needed.
Auto-Tandem Catalysis with Frustrated Lewis Pairs for Reductive Etherification of Aldehydes and Ketones
Bakos, Mária,Gy?m?re, ádám,Domján, Attila,Soós, Tibor
supporting information, p. 5217 - 5221 (2017/04/27)
Herein we report that a single frustrated Lewis pair (FLP) catalyst can promote the reductive etherification of aldehydes and ketones. The reaction does not require an exogenous acid catalyst, but the combined action of FLP on H2, R-OH or H2O generates the required Br?nsted acid in a reversible, “turn on” manner. The method is not only a complementary metal-free reductive etherification, but also a niche procedure for ethers that would be either synthetically inconvenient or even intractable to access by alternative synthetic protocols.
Polystyrene trimethyl ammonium chloride impregnated Rh(0) (Rh@PMe3NCl) as a catalyst and methylating agent for esterification of alcohols through selective oxidation of methanol
Guha, Nitul Ranjan,Bhattacherjee, Dhananjay,Das, Pralay
, p. 2575 - 2580 (2015/06/30)
Rhodium(0) nanoparticle (NP)-impregnated polystyrene trimethyl ammonium chloride (PMe3NCl) resin (Rh@PMe3NCl) under basic conditions acts as a cross-dehydrogenative coupling-methylating (CDCM) agent for the selective oxidation of methanol and its in situ reaction with benzyl/alkyl alcohols allowing methyl group transfer for acetate ester synthesis in a tandem approach. The redox property of methanol which restricts the oxidation of benzyl/alkyl alcohols for product formation is critically investigated.
Eco-efficient preparation of a N-doped graphene equivalent and its application to metal free selective oxidation reaction
Singh, Ajay K.,Basavaraju,Sharma, Siddharth,Jang, Seungwook,Park, Chan Pil,Kim, Dong-Pyo
supporting information, p. 3024 - 3030 (2014/06/10)
Here, we demonstrate that graphene oxide (GO) can be converted to N-doped reduced GO (rGO) that could become a substitute for N-doped graphene. Simultaneous doping and reduction can be accomplished for this purpose by simply mixing GO with hydrazine and then continuously sonicating the solution at 65 °C. A high level of reduction is realized, as evidenced by a carbon to oxygen ratio of 20.7 that compares with the highest value of 15.3 ever reported in solution (water + hydrazine) methods. Nitrogen doping is possible up to 6.3 wt% and the extent of doping can be increased with increasing sonication time. Notably, the simple tuning process of N-doping in GO greatly enhanced the efficiency of the carbocatalyst for various kinds of metal free oxidation reactions and hence is proposed as a suitable candidate for future industrial applications. This journal is the Partner Organisations 2014.
Reductive etherification of aldehydes photocatalyzed by dicarbonyl pentamethylcyclopentadienyl iron complexes
Argouarch, Gilles,Grelaud, Guillaume,Roisnel, Thierry,Humphrey, Mark G.,Paul, Frédéric
supporting information, p. 5015 - 5018 (2012/11/07)
The reductive etherification of aldehydes can be performed by the reaction with dialkylmethylsilanes in the presence of new iron(II) piano-stool catalysts of general formula Cp*Fe(CO)2Ar (Cp * = η5-C5Me5; Ar = Ph, 4-C6H4OCH3, 4-C6H4CH 3, Fc). This transformation is promoted by UV light and affords a simple route for the preparation of unsymmetrical alkyl ethers.
Iron-catalyzed hydrosilylation of esters
Bezier, David,Venkanna, Gopaladasu T.,Castro, Luis C. Misal,Zheng, Jianxia,Roisnel, Thierry,Sortais, Jean-Baptiste,Darcel, Christophe
supporting information; experimental part, p. 1879 - 1884 (2012/09/22)
The first hydrosilylation of esters catalyzed by a well defined iron complex has been developed. Esters are converted to the corresponding alcohols at 100 °C, under solvent-free conditions and visible light activation. Copyright
Practical corey-chaykovsky epoxidation: Scope and limitation
Yu, Hao,Deng, Xiaobing,Cao, Shengli,Xu, Jiaxi
experimental part, p. 509 - 514 (2012/04/11)
Corey-Chaykovsky epoxidation is one of the versatile methods for synthesis of structurally diverse oxiranes. The extension of simplified Corey-Chaykovsky epoxidation has been investigated. Ketones and aromatic aldehydes were epoxidized in satisfactory to excellent yields with trimethylsulfonium iodide as an ylide precursor and crushed potassium hydroxide as a base in tertiary butanol.The scope and limitation of the simplified procedure were examined. The results revealed that the procedure is applicable to the epoxidation of ketones and aromatic aldehydes.
Ferric perchlorate as an efficient and useful catalyst for the selective benzylation and methylation of alcohols with benzyl chloride and methyl iodide
Behbahani, Farahnaz K.,Heravi, Majid M.,Oskooie, Hossien A.
experimental part, p. 181 - 184 (2010/03/26)
A mild and efficient method was developed for selective benzylation and methylation of hydroxyl compounds in the presence of a catalytic amount of ferric perchlorate. We showed that ferric perchlorate was very effective in selectively promoting the benzylation and methylation of primary aliphatic and benzylic alcohols versus secondary aliphatic alcohols and phenolic hydroxy groups. Graphical abstract: [Figure not available: see fulltext.]
A kinetic model for water reactivity (avoiding activities) for hydrolyses in aqueous mixtures - Selectivities for solvolyses of 4-substituted benzyl derivatives in alcohol-water mixtures
Bentley, T. William,Koo, In Sun,Choi, Hojune,Llewellyn, Gareth
, p. 251 - 256 (2008/09/20)
For solvolyses of various benzyl substrates in ethanol-water (EW) and methanol-water (MW) mixtures, product selectivities (S) are reported for chlorides at 75°C defined as follows using molar concentrations: S= ([ether product]/[alcohol product]) × ([water]/[alcohol solvent]). The results support earlier evidence that solvolyses of 4-nitrobenzyl substrates are S N2 processes, which are not susceptible to mechanistic changes over the whole range of solvents from water to alcohol. S values at 25 and/or 45°C in EW and MW, and additional kinetic data including kinetic solvent isotope effects (KSIE) are reported for solvolyses of 4-nitrobenzyl mesylate and tosylate. A kinetic model, explaining both rates and product, is proposed; a general medium effect due to solvent polarity is combined in one parameter with solvent effects on the nucleophilicity of the water and alcohol molecules acting as nucleophiles in SN2 reactions. According to this model, as alcohol is added to water the rate of reaction decreases due to a decrease in solvent polarity, but the nucleophilicity of water increases relative to alcohol. The availability of experimental rate and product data over the whole range of solvent compositions from alcohol to water, reveals limitations of alternative approaches using activities. Copyright
NEW PYRIDINE ANALOGUES
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Page/Page column 191, (2008/06/13)
The present invention relates to certain new pyridin analogues of Formula (I) Chemical formula should be inserted here. Please see paper copy Formula (I) to processes for preparing such compounds, to their utility as P2Y12 inhibitors and as anti-trombotic agents etc, their use as medicaments in cardiovascular diseases as well as pharmaceutical compositions containing them.
