6277-76-5Relevant academic research and scientific papers
High pressure-assisted low-loading asymmetric organocatalytic conjugate addition of nitroalkanes to chalcones
Cholewiak, Agnieszka,Adamczyk, Kamil,Kopyt, Micha?,Kasztelan, Adrian,Kwiatkowski, Piotr
, p. 4365 - 4371 (2018/06/22)
The application of high pressure (up to 9 kbar) allows for relatively fast (1-5 h) and highly enantioselective 1,4-addition of nitromethane and 2-nitropropane to chalcones at room temperature with substantial reduction of catalyst loading (0.2-1 mol% of cinchona alkaloid-based thioureas and squaramides). Various γ-nitroketones were obtained at 9 kbar with high yield and enantioselectivity (up to 98%), whereas in control experiments at atmospheric pressure usually only a small amount (10%) of products were formed after 20 h.
Rasta resin as support for TBD in base-catalyzed organic processes
Bonollo, Simona,Lanari, Daniela,Angelini, Tommaso,Pizzo, Ferdinando,Marrocchi, Assunta,Vaccaro, Luigi
experimental part, p. 216 - 222 (2012/03/08)
Although its intriguing features, such as uniform functionalization through the entire beads and a very high-loading capacity are suitable candidates for solid-phase synthesis and reagent-scavenging, the use of Rasta resin as support for organocatalysis has been little explored. In this contribution, Rasta polymer has been used to preparation of high-loading Rasta-TBD. This catalyst has been able to efficiently promote several organic transformations with constantly good and promising results.
Enantioselective conjugate addition of nitro compounds to α,β-unsaturated ketones: An experimental and computational study
Manzano, Ruben,Andres, Jose M.,Alvarez, Rosana,Muruzabal, Maria D.,De Lera, Angel R.,Pedrosa, Rafael
supporting information; experimental part, p. 5931 - 5938 (2011/07/08)
A series of chiral thioureas derived from easily available diamines, prepared from α-amino acids, have been tested as catalysts in the enantioselective Michael additions of nitroalkanes to α,β-unsaturated ketones. The best results are obtained with the bi
Synthesis and characterization of 5-(2-nitro-1-arylpropyl)-4-aryl-1,2,3- selenadiazoles
Saravanan,Amuthavalli,Muthusubramanian
body text, p. 1144 - 1147 (2010/01/06)
The synthesis and characterization of new 5-(2-nitro-l-arylpropyl)-4-aryl- 1,2,3-selenadiazoles, obtained from the α-functionalised semicarbazones are described. The structures of these compounds have been established by 1H and13C NMR spectral data.
Epi-cinchona based thiourea organocatalyst family as an efficient asymmetric Michael addition promoter: Enantioselective conjugate addition of nitroalkanes to chalcones and α,β-unsaturated N-acylpyrroles
Vakulya, Benedek,Varga, Szilard,Soos, Tibor
, p. 3475 - 3480 (2008/09/20)
(Chemical Equation Presented) A small set of easily available epi-cinchona based thiourea organocatalysts have been synthesized and tested in enantioselective Michael addition of nitroalkanes to chalcones. These bifunctional catalyst systems promoted the
Henry reaction and 1,4-addition of nitroalkanes to α,β- unsaturated carbonyl compounds under the influence of MS 4 A in DMSO
Oriyama, Takeshi,Aoyagi, Masaru,Iwanami, Katsuyuki
, p. 612 - 613 (2008/02/07)
In the presence of MS 4 A in DMSO (dimethyl sulfoxide), Henry reaction with various carbonyl compounds and nitroalkanes proceeded smoothly to give the corresponding β-nitroalcohol without a base catalyst. Moreover, 1,4-additon of nitroalkane to α,β-unsaturated ketones was also performed in DMSO. Copyright
Solvent-free synthesis of γ-nitroketones and γ-nitroesters promoted by the ionic liquid/K2CO3 catalytic system
Zlotin, Sergey G.,Bogolyubov, Andrey V.,Kryshtal, Galina V.,Zhdankina, Galina M.,Struchkova, Marina I.,Tartakovsky, Vladimir A.
, p. 3849 - 3854 (2008/02/10)
A convenient solvent-free synthesis of γ-nitroketones and γ-nitroesters based on the reaction of nitroalkanes with α,β-unsaturated carbonyl compounds in the ultrasonically activated heterogeneous catalytic system 1-butyl-3-methylimidazolium tetrafluorobor
Novel heterobimetallic catalysts for asymmetric Michael reactions
Velmathi,Swarnalakshmi,Narasimhan
, p. 113 - 117 (2007/10/03)
The newly developed chiral catalysts 1 and 2 show opposite enantioselectivity in Michael addition reactions of cyclic enones and malonates resulting in the production of both enantiomers of products in good chemical yield and enantiomeric excess. 27
THE SYNTHESIS AND CHEMISTRY OF AZOLENINES. PART 12. ISOLATION OF INTERMEDIATE 2-HYDROXY-3,4-DIHYDRO-2H-PYRROLES IN THE PAAL-KNORR 1H-PYRROLE SYNTHESIS.
Chiu, Pak-Kan,Sammes, Michael P.
, p. 3531 - 3538 (2007/10/02)
Treatment of 1,4-diketones with liquid ammonia gives high yields of isolable 2-hydroxy-3,4-dihydro-2H-pyrrole intermediates.These intermediates, which do not appear to have been observed previously in the Paal-Knorr synthesis with ammonia, have been fully characterized by i.r. and 1H and 13C n.m.r. spectroscopy; in most cases they decompose quantitatively into 1H-pyrroles on standing.The intermediate from hexane-2,4-dione may also be prepared using concentrated aqueous ammonia.
Tetraphenylphosphonium Hydrogendifluoride: a New Source of Fluoride Ion
Brown, Stephen J.,Clark, James H.
, p. 672 - 673 (2007/10/02)
Tetraphenylphosphonium hydrogendifluoride, a soluble and thermally stable reagent, acts as a source of fluoride ion in a variety of organic reactions.
