6768-20-3Relevant academic research and scientific papers
Metal free biomimetic deaminative direct C-C coupling of unprotected primary amines with active methylene compounds
Ghosh, Santanu,Jana, Chandan K.
supporting information, p. 10153 - 10157 (2019/12/26)
An unprecedented direct C-C coupling reaction of unprotected primary amines with active methylene compounds is reported. The reaction involves a biomimetic deamination of amines which was achieved under conditions free of metallic reagents and strong oxidizing agents. A wide range of primary amines was reacted with different active methylene compounds to provide structurally diverse trisubstituted alkenes and dihydropyridines. A kinetic study revealed an activation barrier of 10.1 kcal mol-1 for the conversion of a key intermediate of the reaction.
Unnatural α-amino ethyl esters from diethyl malonate or ethyl β-bromo-α-hydroxyiminocarboxylate
Coutant, Eloi P.,Hervin, Vincent,Gagnot, Glwadys,Ford, Candice,Baatallah, Racha,Janin, Yves L.
supporting information, p. 2853 - 2860 (2018/11/26)
We have explored here the scope of the age-old diethyl malonate-based accesses to α-amino esters involving Knoevenagel condensations of diethyl malonate on aldehydes, reductions of the resulting alkylidenemalonates, the preparation of the corresponding α-hydroxyimino esters and their final reduction. This synthetic pathway turned out to be general although some unexpected limitations were encountered. The synthetic modifications of some of the intermediates - using Suzuki-Miyaura coupling or cycloadditions - before undertaking the oximation step - provided accesses to further α-amino esters. Moreover, other pathways to α-hydroxyimino esters were explored including an attempt to improve the cycloadditions between ethyl β-bromo-α-hydroxyiminocarboxylate and various alkylfuranes.
A bionic aqueous heterogeneous catalytic system catalytic aromatic aldehydes with malonic acid diester method of the condensation reaction between
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Paragraph 0072, (2018/01/19)
The invention discloses a method for catalyzing the condensation reaction between aromatic aldehyde and malonic diester with a bionic water-containing heterogeneous catalytic system. According to the method, aromatic aldehyde and malonic diester are adopt
Efficient synthesis of β-aryl-γ-lactams and their resolution with (S)-Naproxen: Preparation of (R)- and (S)-Baclofen
Montoya-Balbás, Iris J.,Valentín-Guevara, Berenice,López-Mendoza, Estefanía,Linzaga-Elizalde, Irma,Ordo?ez, Mario,Román-Bravo, Perla
, p. 22028 - 22043 (2016/01/25)
An efficient synthesis of enantiomerically-pure β-aryl-γ-lactams is described. The principal feature of this synthesis is the practical resolution of β-aryl-γ-lactams with (S)-Naproxen. The procedure is based on the Michael addition of nitromethane to benzylidenemalonates, which was easily obtained, followed by the reduction of the γ-nitroester in the presence of Raney nickel and the subsequent saponification/decarboxylation reaction. The utility of this methodology was highlighted by the preparation of enantiomerically-pure (R)- and (S)-Baclofen hydrochloride.
Design and synthesis of 6-oxo-1,4,5,6-tetrahydropyrimidine-5-carboxylate derivatives as neuraminidase inhibitors
Lou, Jun,Yang, Xiaoyan,Rao, Zhigang,Qi, Wenwen,Li, Jinhui,Wang, Haiyu,Li, Yuxi,Li, Jinping,Wang, Zhiming,Hu, Xianming,Liu, Peng,Hong, Xuechuan
, p. 466 - 473 (2014/07/21)
A series of 6-oxo-1,4,5,6-tetrahydropyrimidine-5-carboxylate derivatives were prepared to evaluate their ability of inhibiting neuraminidase (NA) of influenza A virus. All the compounds were synthesized in good yields starting from aldehyde by using a suitable synthetic strategy, which showed moderate inhibitory activity against influenza A NA. Compound 6g exhibited the strongest inhibitory activity against influenza virus A NA (IC50 = 17.64 μM), which indicated pyrimidine ring could be used as a core structure to design novel influenza NA inhibitors.
Chiral-Zn(NTf2)2-complex-catalyzed diastereo- and enantioselective direct conjugate addition of arylacetonitriles to alkylidene malonates
Yao, Jingjing,Liu, Xiaohua,He, Peng,Zhu, Yin,Lian, Xiangjin,Lin, Lili,Feng, Xiaoming
supporting information, p. 16424 - 16430 (2013/12/04)
Chiral N,N′-dioxide/Zn(NTf2)2 complexes were demonstrated to be highly effective in the direct asymmetric conjugate addition of arylacetonitriles to alkylidene malonates under mild conditions. A wide range of substrates were tolerated to afford their corresponding products in moderate-to-good yields with high diastereoselectivities (82:18->99:1 d.r.) and enantioselectivities (81-99 % ee). The reactions performed well, owing to the high Lewis acidity of the metal triflimidate and a ligand-acceleration effect. The N,N′-dioxide also benefited the deprotonation process as a Bronsted base. The catalytic reaction could be performed on the gram-scale with retention of yield, diastereoselectivity, and enantioselectivity. The products that contained functional groups were ready for further manipulation. In addition, a possible catalytic model was proposed to explain the origin of the asymmetric induction. Copyright
A systematic study on Knoevenagel reaction and Nazarov cyclization of less reactive carbonyl compounds using rare earth triflates and its applications
Ilangovan,Muralidharan,Maruthamuthu
experimental part, p. 1000 - 1006 (2012/02/05)
A systematic study of Knoevenagel reaction and Nazarov cyclization was made on variety of less reactive carbonyl compounds such as β-ketoesters, 1,3-diketones and cyclic active methylene compounds using Yb(OTf)3 as the catalyst. Recycling study confirms reusability of the catalyst without much loss of activity.
Asymmetric cyanation of activated olefins with ethyl cyanoformate catalyzed by a modular titanium catalyst
Wang, Jun,Li, Wei,Liu, Yanling,Chu, Yangyang,Lin, Lili,Liu, Xiaohua,Feng, Xiaoming
supporting information; experimental part, p. 1280 - 1283 (2010/06/15)
"Chemical Equation Presented" Asymmetric cyanation of a class of easily available olefins with a favorable cyanide source ethyl cyanoformate (CNCOOEt) was realized by an interesting modular catalyst. High yields and ee values were obtained for a range of substrates under solvent-free and mild reaction conditions. The products obtained could be easily transformed to the enantioenriched useful intermediates 5,6, and pharmaceutically Important γ-aminobutyric acid 7.
Synthesis, Screening, and Molecular Modeling of New Potent and Selective Antagonists at the α1d Adrenergic Receptor
Leonardi, Amedeo,Barlocco, Daniela,Montesano, Federica,Cignarella, Giorgio,Motta, Gianni,Testa, Rodolfo,Poggesi, Elena,Seeber, Michele,De Benedetti, Pier G.,Fanelli, Francesca
, p. 1900 - 1918 (2007/10/03)
In the present study, more than 75 compounds structurally related to BMY 7378 have been designed and synthesized. Structural variations of each part of the reference molecule have been introduced, obtaining highly selective ligands for the α1d adrenergic receptor. The molecular determinants for selectivity at this receptor are essentially held by the phenyl substituent in the phenylpiperazine moiety. The integration of an extensive SAR analysis with docking simulations using the rhodopsin-based models of the three α1-AR subtypes and of the 5-HT1A receptor provides significant insights into the characterization of the receptor binding sites as well as into the molecular determinants of ligand selectivity at the α1d-AR and the 5-HT1A receptors. The results of multiple copies simultaneous search (MCSS) on the substituted phenylpiperazines together with those of manual docking of compounds BMY 7378 and 69 into the putative binding sites of the α1a-AR, α1b-AR, α1d-AR, and the 5-HT1A receptors suggest that the phenylpiperazine moiety would dock into a site formed by amino acids in helices 3, 4, 5, 6 and extracellular loop 2 (E2), whereas the spirocyclic ring of the ligand docks into a site formed by amino acids of helices 1, 2, 3, and 7. This docking mode is consistent with the SAR data produced in this work. Furthermore, the binding site of the imide moiety does not allow for the simultaneous involvement of the two carbonyl oxygen atoms in H-bonding interactions, consistent with the SAR data, in particular with the results obtained with the lactam derivative 128. The results of docking simulations also suggest that the second and third extracellular loops may act as selectivity filters for the substituted phenylpiperazines. The most potent and selective compounds for α1d adrenergic receptor, i.e., 69 (Rec 26D/038) and 128 (Rec 26D/073), are characterized by the presence of the 2,5-dichlorophenylpiperazine moiety.
Lewis acidic ionic liquids for the synthesis of electrophilic alkenes via the Knoevenagel condensation
Harjani, Jitendra R,Nara, Susheel J,Salunkhe, Manikrao M
, p. 1127 - 1130 (2007/10/03)
1-Butyl-3-methylimidazolium chloroaluminate, [bmim]Cl·AlCl3, N = 0.67 and 1-butylpyridinium chloroaluminate, [bpy]Cl·AlCl3, N = 0.67 ionic liquids were found to work well as the Lewis acid catalyst and solvent in the Knoevenagel condensations of benzaldehyde and substituted benzaldehydes with diethyl malonate to give benzylidene malonates. The benzylidene malonates subsequently underwent Michael additions with diethyl malonate. The extent of Michael product formed during the reaction was found to vary with the Lewis acidity and the molar proportion of ionic liquid. The influence of Lewis acidity of the ionic liquid on the Knoevenagel and Michael products is demonstrated. In the case of 2-hydroxyarylaldehydes, the reactions led to the formation of 3-ethoxycarbonyl coumarins under ambient conditions.
