19653-33-9Relevant articles and documents
Selective N-alkylation of indoles with α,β-unsaturated compounds catalyzed by a monomeric phosphate
Sunaba, Hanako,Kamata, Keigo,Mizuno, Noritaka
, p. 2333 - 2338 (2014)
Catalytic N-alkylation of indoles is challenging because the N1 nitrogen atoms are inert toward electrophilic reagents. Herein, an organic-solvent- soluble alkylammonium salt of a simple monomeric phosphate ion, [PO 4]3-, with a high charge density acts as an efficient homogeneous catalyst for selective N-alkylation of indoles with α,β-unsaturated compounds. For the reaction of indole with ethyl acrylate, the turnover number reached up to 36 and the turnover frequency was 216 h-1; these values are the highest among those reported for base-mediated systems so far. In the presence of [PO4]3- ions, various combinations of nitrogen nucleophiles (ten examples) and α,β-unsaturated compounds (four examples) were efficiently converted to the desired N-alkylated products in high yields. NMR and IR spectroscopies showed formation of the indolyl anion through the activation of indole by the [PO4]3- ion, which plays an important role in the present N-alkylation.
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Fuson,Bradley
, p. 602 (1929)
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CATALYSIS OF THE SPECIFIC MICHAEL ADDITION : THE EXAMPLE OF ACRYLATE ACCEPTORS
Cabral, Jose,Laszlo, Pierre,Mahe, Loic,Montaufier, Marie-Therese,Randriamahefa, S. Lalatiana
, p. 3969 - 3972 (1989)
Lewis acids, ferric chloride in particular, catalyze the addition of amine nucleophiles to arcylates.Yields are very good, under mild conditions.Exlusive 1,4-addition occurs, and polymerization is avoided.
A basic ionic liquid as catalyst and reaction medium: A rapid and simple procedure for Aza-Michael addition reactions
Xu, Jian-Ming,Wu, Qi,Zhang, Qing-Yi,Zhang, Fu,Lin, Xian-Fu
, p. 1798 - 1802 (2007)
A fast, mild, and quantitative procedure for Michael addition reactions between various amines and α,β-unsaturated carbonyl compounds and nitriles in the presence of an easily accessible basic ionic liquid - 3-butyl-1-methylimidazolium hydroxide, [bmIm]OH - as both catalyst and reaction medium has been developed. For large-scale reactions the products could be directly distilled from the ionic liquid, allowing the use of organic solvents to be avoided totally. The ionic liquid could be reused at least eight times with consistent activity and was stable during the reaction process. Wiley-VCH Verlag GmbH & Co. KGaA, 2007.
Fast and Efficient Acquisition of Kinetic Data in Microreactors Using In-Line Raman Analysis
Schwolow, Sebastian,Braun, Frank,R?dle, Matthias,Kockmann, Norbert,R?der, Thorsten
, p. 1286 - 1292 (2015)
This study demonstrates that a microreactor setup with fast in-line reaction monitoring by Raman spectroscopy can be a highly efficient laboratory tool for kinetic studies and process development. Using a coaxial probe and commercial spectrometer to perform real-time measurements in the microchannel prevents the need for reaction quenching, sampling, and time-consuming off-line analysis methods such as GC or HPLC. A specially designed, temperature-controlled aluminum plate microreactor was developed and tested in the exothermic synthesis of 3-piperidino propionic acid ethyl ester by Michael addition. In-line measurements through a fused quartz screen in the reactor channel, which had an increasing cross-sectional area, allowed time-series kinetic data to be collected over nearly the full range of reaction conversions. An optimum flow rate range in which nearly ideal plug flow behavior can be assumed was identified. Furthermore, a time gradient was applied to the reactant flow rates, and the product concentration was simultaneously and repeatedly measured at various locations in the reactor channel. With this approach, the experiment duration and material consumption are significantly reduced relative to those of conventional steady-state experiments. Two hundred data points with residence times ranging from 0.3 to 49 s were collected in less than 1 h. Thus, this method can be used for the high-throughput screening of reaction parameters in a microreactor.
A green and convenient approach for the one-pot solvent-free synthesis of coumarins and β-amino carbonyl compounds using Lewis acid grafted sulfonated carbon@titania composite
Kour, Manmeet,Paul, Satya
, p. 327 - 337 (2017/02/10)
Abstract: This paper reports an efficient protocol for the synthesis of coumarins via Pechmann reaction, and β-amino carbonyl compounds via aza-Michael reaction using catalytic amount of solid Lewis acid catalyst, C@TiO2–SO3–SbCl2. Six different catalysts were prepared by covalent immobilization of homogeneous Lewis acids onto sulfonated carbon@titania composite derived from amorphous carbon and nano-titania. Among various catalysts tested, C@TiO2–SO3–SbCl2 showed superior catalytic activity. The catalyst could be recycled without significant loss of its catalytic activity and demonstrated versatile catalysis for a wide range of substrates. Graphical abstract: [Figure not available: see fulltext.]
Room temperature solvent free aza-Michael reactions over nano-cage mesoporous materials
Kalita, Pranjal,Pegu, Choitayna Dev,Dutta, Prantu,Baruah, Pranjal K.
, p. 145 - 150 (2014/08/18)
An efficient highly acidic three dimensional mesoporous aluminosilicate nano-cage material Al-KIT5, exhibited excellent catalytic activity in solvent free room temperature aza-Michael reactions of amines with α,β- unsaturated carbonyl compounds to produce β-amino carbonyl compounds with 100% product selectivity in a short reaction time. The high acidity, 3D pores, and a huge space in the nano-cages materials make them attractive candidate for carrying out important organic reactions. The catalyst provide a simple, easy to handle method, and could be used to solve the problems of corrosion, toxicity, waste production, and a high cost that are being currently encountered by the conventional homogeneous catalysts.
