1212469-34-5Relevant articles and documents
Densely substituted l -proline esters as catalysts for asymmetric michael additions of ketones to nitroalkenes
Ruiz-Olalla, Andrea,Retamosa, María De Gracia,Cossío, Fernando P.
, p. 5588 - 5599 (2015)
Homochiral methyl 4-aminopyrrolidine-2-carboxylates are readily obtained by means of asymmetric (3 + 2) cycloadditions between azomethine ylides and nitroalkenes, followed by catalytic hydrogenation of the intermediate 4-nitro cycloadducts. These 4-aminopyrrolidine-2-carboxylate esters belong to the l-series of natural amino acids and catalyze asymmetric Michael additions of ketones to nitroalkenes. However, the enantioselectivity observed with these novel unnatural organocatalysts is opposite to that obtained with l-proline. Since both 4-nitro and 4-amino l-proline esters are efficient organocatalysts of aldol reactions, these results permit to modulate asymmetric quimioselective aldol and conjugate addition reactions.
Pyrrolidine-pyridinium based organocatalysts for highly enantioselective Michael addition of cyclohexanone to nitroalkenes
Xu, Dan-Qian,Wang, Bing-Tao,Luo, Shu-Ping,Yue, Hua-Dong,Wang, Li-Ping,Xu, Zhen-Yuan
, p. 1788 - 1794 (2007)
A novel class of pyrrolidine-pyridinium based organocatalysts has been developed and demonstrated to efficiently catalyze the asymmetric Michael addition reactions of unmodified cyclohexanone to nitroalkenes in the ionic liquid BMImBF4 with up
Chiral Pyrrolidine Bridged Polyhedral Oligomeric Silsesquioxanes as Heterogeneous Catalysts for Asymmetric Michael Additions
Luanphaisarnnont, Torsak,Hanprasit, Sasikarn,Somjit, Vetiga,Ervithayasuporn, Vuthichai
, p. 779 - 786 (2018)
Abstract: A chiral pyrrolidine bridged polyhedral oligomeric silsesquioxane (SQ) was synthesized, characterized, and used as an effective heterogeneous catalyst. The synthesis involves two simple steps: nucleophilic substitution between benzylchloride fun
Remarkable enhancement of nucleophilicity of tin enolates toward nitro-or cyanoalkenes by tetrabutylammonium halides
Yasuda, Makoto,Ohigashi, Noriyuki,Baba, Akio
, p. 1266 - 1267 (2000)
The reaction of tin enolates with nitroalkenes was effectively catalyzed by tetrabutylammonium bromide (Bu4NBr) to give γ-nitroketones. When the substituted tin enolates at the β-carbon in the olefinic moiety were used, the diastereoselective a
Prolinol tert-butyldiphenylsilyl ether as organocatalyst for the asymmetric michael addition of cyclohexanone to nitroolefins
Liu, Fengying,Wang, Shiwen,Wang, Ning,Peng, Yungui
, p. 2415 - 2419 (2007)
The direct Michael additions of cyclohexanone to nitroolefins catalyzed by prolinol tert-butyldiphenylsilyl ether were conducted successfully in good yields (up to 99%) and high stereo-selectivities (up to 98:2 diastereomeric ratio and 95% enantiomeric ex
Highly enantioselective water-compatible organocatalyst for Michael reaction of ketones to nitroolefins
Vishnumaya,Singh, Vinod K.
, p. 1117 - 1119 (2007)
(Chemical Equation Presented) A chiral diamine was found to catalyze enantioselective addition of ketones to nitroolefins in aqueous/saline/organic media. The products were obtained with excellent diastereoselectivities (syn/anti = 99:1) and enantioselect
A new kind of organophosphorus compounds as an efficient catalyst for asymmetric C-C bond formation reactions
Xu, Da-Zhen,Liu, Yingjun,Li, Hui,Wang, Yongmei
, p. 8899 - 8903 (2010)
A new class of chiral pyrrolidine-phosphite organocatalysts, available from commercially starting materials, has been synthesized and shown to be good catalytic activity for asymmetric Michael and Aldol reactions. The reactions proceeded to give the produ
Enantioselective nitro-Michael reactions catalyzed by short peptides on water
Freund, Matthias,Schenker, Sebastian,Tsogoeva, Svetlana B.
, p. 4279 - 4284 (2009)
Simple unmodified N-proline-based di- and tripeptides in combination with sodium hydroxide additive catalyze the asymmetric Michael reaction of ketones with nitroolefins to furnish the corresponding γ-nitroketones with up to 99% yield, 99:1 dr and 70% ee
Silica gel-immobilized multidisciplinary materials applicable in stereoselective organocatalysis and HPLC separation
T?ma,Kohout
, p. 1174 - 1181 (2018)
In this pilot study, we present novel bifunctional silica gel-immobilized materials applicable as heterogeneous organocatalysts and stationary phases in HPLC. The materials provided high stereoselectivity in both batch and continuous flow catalysis of a m
Novel polycarbonate copolymer as organocatalyst for aldol and Michael reaction
Bugde, Sandesh,Majik, Mahesh,Mandrekar, Vinod,Nadkarni, Vishnu,Tilve, Santosh
, p. 2536 - 2545 (2013)
A new polymeric organocatalyst is prepared by free radical copolymerization of allyl diglycol carbonate (ADC) and Boc-protected allyl prolinate and evaluated as a chiral catalyst for aldol and Michael reaction. Copyright
Novel bifunctional organocatalyst using sulfamide as hydrogen bonding donor: Application in asymmetric michael addition of cyclic ketones to nitroolefins
Deng, Fei,Liu, Hong-Ying
, p. 767 - 774 (2012)
A chiral bifunctional organocatalyst using sulfamide as novel type of hydrogen bonding donor has been developed. This catalyst was found to efficiently catalyze the Michael addition of cyclic ketones to nitroolefins in water, and the products were obtaine
Novel pyrrolidine-aminobenzimidazole bifunctional organocatalysts for asymmetric nitro-Michael reactions in brine
Lin, Jian,Tian, Hua,Jiang, Yi-Jun,Huang, Wen-Bo,Zheng, Liang-Yu,Zhang, Suo-Qin
, p. 1434 - 1440 (2011)
A new family of bifunctional organocatalysts with conformationally rigid H-bond donors was successfully synthesized and applied to the aqueous phase Michael reactions of cyclohexanone with nitroolefins. The corresponding products were obtained with high e
Organocatalysts wrapped around by poly(ethylene glycol)s (PEGs): A unique host-guest system for asymmetric Michael addition reactions
Xu, Dan Qian,Luo, Shu Ping,Wang, Yi Feng,Xia, Ai Bao,Yue, Hua Dong,Wang, Li Ping,Xu, Zhen Yuan
, p. 4393 - 4395 (2007)
Asymmetric Michael addition reactions of unmodified ketones to nitroalkenes were performed in PEGs catalyzed by novel pyrrolidinyl-thioimidazolium salts to give products in up to 97% yield and 99% enantioselectivity; ESI mass spectrometric detection for t
The use of N-Alkyl-2,2′-bipyrrolidine derivatives as organocatalysts for the asymmetric michael addition of ketones and aldehydes to nitroolefins
Andrey, Olivier,Alexakis, Alexandre,Tomassini, Axel,Bernardinelli, Gerald
, p. 1147 - 1168 (2004)
The direct Michael addition of aldehydes and ketones to nitroolefins, catalyzed by N-i-Pr-2,2′-bipyrrolidine, is described. The desired 1,4-adducts are obtained in excellent yields with enantioselectivities up to 95% ee and dr up to 95:5 of the syn aldehyde addition product. An unexpected inversion of diastereoselectivity was observed for the addition of α-hydroxy ketones to β-arylnitroolefins with enantioselectivities up to 98% ee. The formation of an internal hydrogen bond between the OH group of the α-hydroxy ketone and the tertiary nitrogen of the catalyst leads to the formation of a rigid cis enamine intermediate that accounts for the inversion of the expected diastereoselectivity and the very high ees.
Continuous asymmetric Michael addition of ketones to β-nitroolefins(1R,2R)-(+)-1,2-DPEN-modified sulfonic acid resin
Tian, Jun,Zhang, Chao,Qi, Xuefei,Yan, Xilong,Li, Yang,Chen, Ligong
, p. 724 - 728 (2015)
A trifunctional catalyst was successfully prepared by bonding (1R,2R)-(+)-1,2-DPEN to sulfonic acid resin. The catalyst was characterized by elemental analysis, thermogravimetric (TG) analysis and infrared (IR) spectroscopy. The results indicated the coex
Surfactant-type asymmetric organocatalyst: Organocatalytic asymmetric Michael addition to nitrostyrenes in water
Luo, Sanzhong,Mi, Xueling,Liu, Song,Xu, Hui,Cheng, Jin-Pei
, p. 3687 - 3689 (2006)
A surfactant-type asymmetric organocatalyst (STAO) catalyzed highly efficient Michael addition to nitroalkenes with high stereoselectivities in water without using any organic solvents or additional additives. The Royal Society of Chemistry 2006.
A highly efficient and recyclable ionic liquid anchored pyrrolidine catalyst for enantioselective Michael additions
Miao, Tao,Wang, Lei,Li, Pinhua,Yan, Jincan
, p. 3828 - 3834 (2008)
Highly enantioselective Michael addition of cyclohexanone to aryl nitroolefins in the presence of an ionic liquid anchored pyrrolidine (10 mol%) and TFA (5 mol%) generated the corresponding adducts in high yields (up to 95%) with excellent diastereoselect
Chiral amphiphilic secondary amine-porphyrin hybrids for aqueous organocatalysis
Arlegui, Aitor,Torres, Pol,Cuesta, Victor,Crusats, Joaquim,Moyano, Albert
, (2020)
Two chiral proline-derived amphiphilic 5-substituted-10,15,20-tris(4-sulfonatophenyl)porphyrins were prepared, and their pH-dependent supramolecular behavior was studied. In neutral aqueous solutions, the free-base form of the hybrids is highly soluble, a
2-[1-(Dimethylamino)ethyl]ferrocenylphosphinic acid as an organocatalyst of Michael and Friedel—Crafts reactions
Gilmanova, L. H.,Miluykov, V. A.,Shekurov, R. P.,Zagidullin, A. A.
, p. 1415 - 1417 (2021)
Racemic 2-[1-(dimethylamino)ethyl]ferrocenylphosphinic acid was tested as an organocatalyst in the Michael and Friedel—Crafts reactions. The use of this zwitterion provides 78% conversion in the Michael reaction between cyclohexanone and β-nitrostyrene, a
Polystyrene supported benzoylthiourea—pyrrolidine organocatalyst for the enantioselective Michael addition
Androvi?, Ladislav,Drabina, Pavel,Svobodová, Markéta,Sedlák, Milo?
, p. 782 - 787 (2016)
Herein the preparation of a swellable pearl-like copolymer of styrene with anchored (S)-1-benzoyl-3-(pyrrolidine-2-ylmethyl)thiourea (20–600?μm) and its application as a recyclable organocatalyst for the Michael addition of ketones to functionalized β-nit
Organocatalytic Activation of Diethyl Glutaconate for the Diastereo- and Enantioselective Assembly of NH-Free 2,3,4-Trisubstituted Pyrrolidines
Quintard, Adrien,Rodriguez, Jean
, p. 722 - 725 (2017)
Organocatalyzed enantioselective consecutive Michael addition of diethyl glutaconate to a nitro-olefin/reductive cyclization sequence has been developed, directly providing NH-free trans,trans-2,3,4-trisubstituted pyrrolidines with typically >88:12 dr and >90% ee. The obtained structures are closely related to several molecules with high biological profiles, holding great promise for medicinal chemistry. In addition, their potential as direct organocatalysts in the enantioselective Michael addition promoted by enamine activation is also reported.
Biomimetic asymmetric Michael addition reactions in water catalyzed by amino-containing β-cyclodextrin derivatives
Zhu, Qingying,Shen, Haimin,Yang, Zhujin,Ji, Hongbing
, p. 1227 - 1234 (2016)
Nine β-cyclodextrin derivatives containing an amino group were synthesized via nucleophilic substitution from mono(6-O-p-tolylsulfonyl)-β-cyclodextrin and used in asymmetric biomimetic Michael addition reactions in water at room temperature. The mechanism responsible for the moderate activity and enantioselectivity of the β-cyclodextrin derivatives was explored using nuclear magnetic resonance spectroscopy, namely 2D 1H rotating-frame overhauser effect spectroscopy (ROESY), ultraviolet absorption spectroscopy, and quantum chemical calculations, which provide a useful technique for investigating the formation of inclusion complexes. The effects of the pH of the reaction medium, the β-cyclodextrin derivative dosage, the structure of the modifying amino group, and various substrates on the yield and enantioselectivity were investigated. The results indicated that these factors had an important effect on the enantiomeric excess (ee) in the reaction system. Experiments using a competitor for inclusion complex formation showed that a hydrophobic cavity is necessary for enantioselective Michael addition. A comparison of the reactions using 4-nitro-β-nitrostyrene and 2-nitro-β-nitrostyrene showed that steric hindrance improved the enantioselectivity. This was verified by the optimized geometries obtained from quantum chemical calculations. An ee of 71% was obtained in the asymmetric Michael addition of cyclohexanone and 2-nitro-β-nitrostyrene, using (S)-2-aminomethylpyrrolidine-modified β-CD as the catalyst, in an aqueous buffer solution, i.e., CH3COONa-HCl (pH 7.5).
Tryptophan/copper-catalyzed aromatization reaction of chiral cyclohexanones to phenols
Liu, Xue-Li,Zhang, Xiao-Long,Xia, Ai-Bao,Guo, Yan-Jun,Meng, Chen-Hong,Xu, Dan-Qian
, p. 5126 - 5130 (2017)
By merging organocatalysis with copper catalysis, a highly efficient stereospecific approach for the synthesis of chiral phenols from cyclohexanones has been developed for the first time. The aromatization reaction proceeds through the in situ formation of enone intermediates and further subsequent bromination/dehydrobromination reactions. And a series of functionalized phenol derivatives are obtained in good yields (up to 89%) and good to excellent enantioselectivities (up to 99% ee).
Stereoselective michael addition of carbonyl compounds to (E)-β-nitrostyrene catalysed by N-toluensulfonyl-l-proline amide in ionic liquids
Meciarova, Maria,Hubinska, Katarina,Toma, Stefan,Koch, Burkhard,Berkessel, Albrecht
, p. 1181 - 1186 (2007)
N-Toluensulfonyl-l-prolin amide was tested as catalyst in the enantioselective Michael addition of carbonyl compounds to (E)-β- nitrostyrene in nine ionic liquids under different reaction conditions. The reaction rates and enantioselectivities were strong
C2-symmetric sulfonamides as homogeneous and heterogeneous organocatalysts that mimic enzymes in enantioselective Michael additions
Cruz, Harold,Servín, Felipe A.,Madrigal, Domingo,Chávez, Daniel,Perez-Sicairos, Sergio,Aguirre, Gerardo,Cooksy, Andrew L.,Somanathan, Ratnasamy
, p. 1036 - 1044 (2018)
Herein, we report the synthesis of C2-symmetric sulfonamides as homogeneous and heterogeneous organocatalysts and their application in the enantioselective conjugate 1,4-Michael addition of carbonylic nucleophiles to β-nitrostyrene. Organocatal
Primary Amine Catalyzed Activation of Carbonyl Compounds: A Study on Reaction Pathways and Reactive Intermediates by Mass Spectrometry
Iazzetti, Antonia,Mazzoccanti, Giulia,Bencivenni, Giorgio,Righi, Paolo,Calcaterra, Andrea,Villani, Claudio,Ciogli, Alessia
supporting information, (2021/12/01)
The field of organocatalysis is expanding at a fast pace. Its growth is sustained by major stimuli, such as the effort toward an understanding of the mechanisms of reaction and catalytic processes in general, the elucidation of basic properties leading to stereocontrol and the search for broad applicability and scalability of the synthetic methodology. This paper reports a thorough study based on ESI-MS spectrometry of amino-organocatalyzed model reactions under different experimental conditions. Off-line reaction monitoring of mixtures containing different catalytic systems, by ESI-MSn showed the presence of several putative intermediate species, either in their protonated or sodiated forms. In addition, enantioselective chromatography of crude reactions provides the stereochemical outcome of asymmetric reactions. The bulk of the data collected offers a clue of the intricate pathways occurring in solution for the studied reactions.
Novel C2-symmetric phenylglycine derivatives as organocatalysts of the Michael reaction between nitroalkenes and ketones
Kostenko, A. A.,Kucherenko, A. S.,Kuznetsova, O. Yu.,Zlotin, S. G.
, p. 885 - 889 (2021/06/07)
A comprehensive study of the activity of the amide-type organocatalysts based on (R)- and (S)-phenylglycine and 1,2-di(2-pyridyl)-1,2-diaminoethane in the asymmetric Michael reaction between various nitroalkenes and ketones was carried out. The products o
Chiral anthranilic pyrrolidine as custom-made amine catalyst for enantioselective Michael reaction of nitroalkenes with carbonyl compounds
Moriyama, Katsuhiko,Oka, Yukari,Tsuzuki, Seiji
supporting information, p. 11457 - 11460 (2021/11/12)
A chiral anthranilic pyrrolidine catalyst as a custom-made amine-catalyst was developed for the enantio- and diastereo selective Michael reaction of nitroalkenes with carbonyl compounds. In particular, a peptide-like catalyst in which an α-amino acid is a