- Arylsulfochlorination of β-aminopropioamidoximes giving 2-aminospiropyrazolylammonium arylsulfonates
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The reaction of P-(morpholin-1-yl)propioamidoxime with aromatic sulfonyl chlorides (p-XC6H4SO2Cl; X = CH3O, CH3, H, Br, Cl, NO2) in chloroform in the presence of triethyl-amine does not produce expected O-arylsulfonyl-β-(morpholin-1-yl)propioamidoximes; instead, this reaction affords isomers of the latter compounds, 2-amino-8-oxa-l,5-diazaspiro[4.5]dec-1-ene-5-ammonium arylsulfonates. The structures of the reaction products were established by physicochemical methods, spectroscopy, and X-ray diffraction.
- Kainarbayeva, Zh. N.,Kayukova, L. A.,Myrzabek, A. B.,Praliyev, K. D.
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Read Online
- New asymmetrical morpholinium- and 1,1-dioxidothiomorpholinium-based dicationic ionic liquid: structure, thermophysical and electrochemical properties of propylene carbonate solutions
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A new asymmetrical 1,1-dioxidothiomorpholinium- and morpholinium-based dicationic ionic liquid (4-ethyl-4-[3-(4-ethyl-1,1-dioxidothiomorpholin-4-ium-4-yl)propyl]morpholin-4-ium tetrafluoroborate (EtDTMC3EtM·2BF4)) was synthesized in four stages and characterized by 1H, 13C, 1H,1H–COSY NMR, single X-ray diffraction, XPS spectroscopy and simultaneous thermal analysis. Electrical conductivities of several EtDTMC3EtM·2BF4 solutions in propylene carbonate (PC) were measured in the 298 – 368 K temperature range and analyzed using the Arrhenius, Litovitz, and Vogel–Fulcher–Tammann (VFT) equations.
- Arkhipova, Ekaterina A.,Ivanov, Anton S.,Kupreenko, Stepan Yu.,Levin, Mikhail M.,Lyssenko, Konstantin A.,Maslakov, Konstantin I.,Savilov, Serguei V.
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- Ruthenium (II) β-diketimine as hydroamination catalyst, crystal structure and DFT computations
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A new half-sandwich ruthenium (II) complex containing β-diketiminate ligand has been synthesized and used for hydroamination of acrylonitrile with aromatic and aliphatic amines. The catalytic activity of prepared complex was compared with a series of ruthenium complexes of β-diketiminate ligands, and the effect of electronic and steric properties of these ligands on catalytic activity of their complexes was investigated. Replacement of H atom in α position of β-diketiminate with (CF3) as an electron-withdrawing group leads to decreasing the reaction yield, and on the other hand, electron-donating group (CH3) has the opposite effect. In addition, crystal structure of [Ru(p-cymen)Cl(LH,Cl)] was determined by single X-ray crystallography. Hirshfeld surface analysis has been performed to determine the dominate interactions in molecular crystal. Furthermore, density functional, QTAIM and energy calculations have been carried out, to get the detailed insight into electronic and bonding characteristics of titled compound.
- Dindar, Sara,Nemati Kharat, Ali,Safarkoopayeh, Barzin,Abbasi, Alireza
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p. 403 - 413
(2021/04/26)
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- Bio-heterogeneous Cu(0)NC@PHA for n-aryl/alkylation at room temperature
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A pure cellulose was derived from waste fibre and it was chemically modified to a hydroxamic acid ligand. The poly(hydroxamic acid) was treated with an aqueous copper solution to afford the greenish stable five-membered copper complex; namely Cu(II)@PHA. Further, the Cu(II)@PHA was treated with a reducing agent hydrazine hydride to give brown colour cellulose supported copper nanocomplex (Cu(0)NC@PHA). The Cu(0)NC@PHA was characterised by ATR-FTIR, FE-SEM & EDS, TEM, ICP-OES, TGA, XRD and XPS analyses. The cellulose-based Cu(0)NC@PHA was used for the n-aryl/alkylation (Michael addition) reaction with a variety of α,β-unsaturated Michael acceptors to produce the corresponding n-aryl/alkyl products with an excellent yield at room temperature. The Cu(0)NC@PHA showed extraordinary stability and it was easily filtered out from the reaction mixture and may potentially recycled up to five times without loss of its original catalytic ability.
- Jian Fui, Choong,Lutfor Rahman, Md,Musta, Baba,Sani Sarjadi, Mohd,Sarkar, Shaheen M.,Xin Ting, Tang
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- Inhibitor design to target a unique feature in the folate pocket of Staphylococcus aureus dihydrofolate reductase
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Staphylococcus aureus (Sa) is a serious concern due to increasing resistance to antibiotics. The bacterial dihydrofolate reductase enzyme is effectively inhibited by trimethoprim, a compound with antibacterial activity. Previously, we reported a trimethoprim derivative containing an acryloyl linker and a dihydophthalazine moiety demonstrating increased potency against S. aureus. We have expanded this series and assessed in vitro enzyme inhibition (Ki) and whole cell growth inhibition properties (MIC). Modifications were focused at a chiral carbon within the phthalazine heterocycle, as well as simultaneous modification at positions on the dihydrophthalazine. MIC values increased from 0.0626–0.5 μg/mL into the 0.5–1 μg/mL range when the edge positions were modified with either methyl or methoxy groups. Changes at the chiral carbon affected Ki measurements but with little impact on MIC values. Our structural data revealed accommodation of predominantly the S-enantiomer of the inhibitors within the folate-binding pocket. Longer modifications at the chiral carbon, such as p-methylbenzyl, protrude from the pocket into solvent and result in poorer Ki values, as do modifications with greater torsional freedom, such as 1-ethylpropyl. The most efficacious Ki was 0.7 ± 0.3 nM, obtained with a cyclopropyl derivative containing dimethoxy modifications at the dihydrophthalazine edge. The co-crystal structure revealed an alternative placement of the phthalazine moiety into a shallow surface at the edge of the site that can accommodate either enantiomer of the inhibitor. The current design, therefore, highlights how to engineer specific placement of the inhibitor within this alternative pocket, which in turn maximizes the enzyme inhibitory properties of racemic mixtures.
- Muddala, N. Prasad,White, John C.,Nammalwar, Baskar,Pratt, Ian,Thomas, Leonard M.,Bunce, Richard A.,Berlin, K. Darrell,Bourne, Christina R.
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- Efficient protocol for Aza-Michael addition of N-heterocycles to α,β-unsaturated compound using [Ch]OH and [n-butyl urotropinium]OH as basic ionic liquids in aqueous/solvent free conditions
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The present work emphasizes on a green methodology using designed and synthesized basic ionic liquid, [n-butyl Urotropinium]OH, and commercially available aqueous solution of choline hydroxide [Ch]OH as catalysts for executing Aza-Michael addition of N-heterocycles to α,β-unsaturated compounds at room temperature. The highlighting features of these catalysts include using low concentration of both catalysts along with [Ch]OH being low cost and biodegradable, [n-butyl Urotropinium]OH significantly enhancing the high substrate/catalyst ratio to obtain the desired products in high yield and purity in most cases. Further, both catalysts were recyclable and recoverable up to five cycles.
- Kumar, Sitanshu,Kaur, Amanpreet,Singh, Vasundhara
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p. 193 - 201
(2019/01/24)
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- Late Stage Functionalization of Secondary Amines via a Cobalt-Catalyzed Electrophilic Amination of Organozinc Reagents
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A general preparation of polyfunctional hydroxylamine benzoates from the corresponding secondary amines is reported. This convenient synthesis allows the setup of a late-stage functionalization of various secondary amines, including pharmaceuticals and peptidic derivatives. Thus, a cross-coupling of hydroxylamine benzoates with various alkyl-, aryl-, and heteroaryl-zinc chlorides in the presence of 5 mol % CoCl2 (25 °C, 2 h) provides a range of polyfunctional tertiary amines. This method was used to prepare penfluridol and gepirone.
- Gra?l, Simon,Chen, Yi-Hung,Hamze, Clémence,Tüllmann, Carl Phillip,Knochel, Paul
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supporting information
p. 494 - 497
(2019/01/14)
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- A Commercially Available and User-Friendly Catalyst for Hydroamination Reactions under Technical Conditions
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The activity of a simple, commercially available copper salt, [Cu(NCMe)4](BF4) in intramolecular hydroamination reactions of alkynes and allenes is presented. Reactions were successfully carried out in technical acetonitrile in the presence of air. While attempts of alkene hydroamination failed, this catalyst was also found active in intermolecular aza-Michael reactions.
- Zelenay, Benjamin,Munton, Peter,Tian, Xiaojie,Díez-González, Silvia
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p. 4725 - 4730
(2019/08/01)
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- TiCl2(OTf)-SiO2: A solid stable lewis acid catalyst for Michael addition of α-Aminophosphonates, Amines, Indoles and Pyrrole
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TiCl2(OTf)-SiO2 is simply prepared by immobilization of TiCl3(OTf) on silica gel surface and introduced as a non-hygroscopic Lewis acid catalyst for C-N and C-C bond formation via Michael addition reaction. A variety of structurally diverse nitrogen nucleophiles including α-aminophosphonates, aliphatic and aromatic amines and imidazole were evaluated as Michael donors. Friedel–Crafts alkylation of indoles and pyrrole was also investigated through Michael addition reaction in the presence of TiCl2(OTf)-SiO2 as a catalyst. The reactions were conducted at room temperature or 60 °C under solvent-free conditions and the desired Michael adducts were obtained in high to excellent yields.
- Firouzabadi, Habib,Iranpoor, Naser,Farahi, Soghra
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p. 317 - 323
(2018/02/06)
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- Palladium nanocatalysts in glycerol: Tuning the reactivity by effect of the stabilizer
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Palladium nanoparticles (PdNPs) prepared in neat glycerol containing TPPTS (tris(3-sulfophenyl)phosphine trisodium salt) or cinchona-based alkaloids (cinchonidine, quinidine) as capping agents, were applied as catalysts in fluoride-free Hiyama couplings and conjugate additions with the aim of evaluating the influence of the stabilizer in the catalytic reactivity. Therefore, PdNPs stabilized by phosphine favored C–C cross-couplings, whereas those containing alkaloids showed enhanced suitability for C–C homo-couplings and conjugate additions. The metal/stabilizer coordination mode, i.e. Pd–P dative bond and π-π interaction between quinoline moiety and palladium surface, is certainly key for the stabilization of different active metallic species and then promoting distinctive catalytic pathways.
- Reina, Antonio,Serrano-Maldonado, Alejandro,Teuma, Emmanuelle,Martin, Erika,Gómez, Montserrat
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- Halogenated trimethoprim derivatives as multidrug-resistant Staphylococcus aureus therapeutics
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Incorporation of halogen atoms to drug molecule has been shown to improve its properties such as enhanced in membrane permeability and increased hydrophobic interactions to its target. To investigate the effect of halogen substitutions on the antibacterial activity of trimethoprim (TMP), we synthesized a series of halogen substituted TMP and tested for their antibacterial activities against global predominant methicillin resistant Staphylococcus aureus (MRSA) strains. Structure-activity relationship analysis suggested a trend in potency that correlated with the ability of the halogen atom to facilitate in hydrophobic interaction to saDHFR. The most potent derivative, iodinated trimethoprim (TMP-I), inhibited pathogenic bacterial growth with MIC as low as 1.25 μg/mL while the clinically used TMP derivative, diaveridine, showed resistance. Similar to TMP, synergistic studies indicated that TMP-I functioned synergistically with sulfamethoxazole. The simplicity in the synthesis from an inexpensive starting material, vanillin, highlighted the potential of TMP-I as antibacterial agent for MRSA infections.
- Nilchan, Napon,Phetsang, Wanida,Nowwarat, Taechin,Chaturongakul, Soraya,Jiarpinitnun, Chutima
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p. 5343 - 5348
(2018/05/25)
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- A Thieno[2,3- d]pyrimidine Scaffold Is a Novel Negative Allosteric Modulator of the Dopamine D2 Receptor
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Recently, a novel negative allosteric modulator (NAM) of the D2-like dopamine receptors 1 was identified through virtual ligand screening. This ligand comprises a thieno[2,3-d]pyrimidine scaffold that does not feature in known dopaminergic ligands. Herein, we provide pharmacological validation of an allosteric mode of action for 1, revealing that it is a NAM of dopamine efficacy and identify the structural determinants of this allostery. We find that key structural moieties are important for functional affinity and negative cooperativity, while functionalization of the thienopyrimidine at the 5- and 6-positions results in analogues with divergent cooperativity profiles. Successive compound iterations have yielded analogues exhibiting a 10-fold improvement in functional affinity, as well as enhanced negative cooperativity with dopamine affinity and efficacy. Furthermore, our study reveals a fragment-like core that maintains low μM affinity and robust negative cooperativity with markedly improved ligand efficiency.
- Fyfe, Tim J.,Zarzycka, Barbara,Lim, Herman D.,Kellam, Barrie,Mistry, Shailesh N.,Katrich, Vsevolod,Scammells, Peter J.,Lane, J. Robert,Capuano, Ben
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p. 174 - 206
(2018/05/14)
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- Tapioca cellulose based copper nanoparticles for chemoselective N-alkylation
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Biomaterials as a support for catalysts are of prime importance. Tapioca root which is an abundant biopolymer source was used to synthesize cellulose supported bio-heterogeneous poly(hydroxamic acid) copper nanoparticles (CuN@PHA) and was characterized by Fourier transform infrared spectroscopy (FTIR), ultraviolet-visible spectroscopy (UV-Vis), field emission scanning electron microscopy (FESEM), X-ray photoelectron spectroscopy (XPS), inductively coupled plasma atomic emission spectroscopy (ICP-AES), transmission electron microscopy (TEM) analyses. The tapioca cellulose supported CuN@PHA (50 mol ppm) effectively catalyzed N-alkylation reaction of aliphatic amines with α,β-unsaturated compounds to give the corresponding alkylated products. High yields up to 95% were achieved for the converted products. The reusability of the cellulose supported nanoparticles was found to be excellent with no significant reduction of its catalytic activity over several cycles. The catalyst showed high catalytic activity having turnover number (TON) 18000 and turnover frequency (TOF) 2250 h-1.
- Islam, Md. Shaharul,Mandal, Bablu Hira,Biswas, Tapan Kumar,Rahman, Md. Lutfor,Rashid,Tan, Suat-Hian,Sarkar, Shaheen M.
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p. 550 - 557
(2017/01/05)
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- 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
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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.]
- Kour, Manmeet,Paul, Satya
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p. 327 - 337
(2017/02/10)
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- Nickel(II) N-Heterocyclic Carbene Complexes: Versatile Catalysts for C–C, C–S and C–N Coupling Reactions
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A variety of NiII complexes with a wide range of electronic and steric properties, bearing picolylimidazolidene ligands (a–g) and Cp (Cp = η5-C5H5; 2a–f) or Cp* (Cp* = η5-C5Me5; 3a, c, g) groups, have been synthesised and characterised by using NMR spectroscopy and single-crystal X-ray crystallography. The complexes have been used as precatalysts for a wide range of catalytic transformations, which most likely involve a Ni0/NiII catalytic cycle. In particular, the new well-defined 2a, 2c, 3a and 3c complexes have demonstrated great efficiency and versatility towards Suzuki–Miyaura coupling reactions, hydroamination of activated olefins and C–S cross-coupling reactions of aryl halides and thiols under mild conditions.
- Junquera, Lourdes Benítez,Fernández, Francys E.,Puerta, M. Carmen,Valerga, Pedro
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supporting information
p. 2547 - 2556
(2017/05/29)
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- Waste corn-cob cellulose supported bio-heterogeneous copper nanoparticles for aza-Michael reactions
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Bio-heterogeneous poly(amidoxime) copper nanoparticles were prepared on the modified surface of waste corn-cob cellulose through a graft copolymerization process. The Cu-nanoparticles (0.05 mol% to 50 mol ppm) selectively promoted the aza-Michael reaction of aliphatic amines to give the corresponding alkylated products at room temperature in methanol. The supported nanoparticles were easy to recover and reused eight times without a significant loss of their activity.
- Sarkar, Shaheen M.,Sultana,Biswas, Tapan Kumar,Rahman, Md. Lutfor,Yusoff, Mashitah Mohd
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p. 497 - 502
(2016/01/12)
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- [CH3COO]: Efficient and recyclable catalyst for aza-Michael addition of α, β-unsaturated compounds and amines under solvent-free conditions
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The recyclable ionic liquid [ADPQ][CH3COO] has been used as catalyst for aza-Michael addition of amines to α, β-unsaturated compounds to produce β-amino compounds. The reactions were complete in a few hours with high yields. The ionic liquid can be recycled and reused six times without noticeable decrease of catalytic activity.
- Gao, Xiaochong,Gao, Ruichang
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p. 9101 - 9112
(2015/03/04)
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- Synthesis of a crosslinked polymer with a benzyl(triphenyl)phosphonium ionic liquid moiety and its catalytic activity
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A novel crosslinked polymer with a benzyl(triphenyl)phosphonium ionic liquid moiety was synthesized from triphenylphosphine and p-xylylene dichloride. The bulky IL molecules were inlaid in the polymeric framework, which avoided pore blocking and IL moiety release. The polymer had a high BET surface area and accessible active sites. The polymer was applied to catalyze the aza-Michael additions and gave average yields over 95.0% in several minutes. The polymer had several advantages such as high BET surface area, high activity and high stability, which hold great potential for green chemical processes.
- Liang, Xuezheng
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p. 99448 - 99453
(2015/12/04)
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- Palladium nanoparticles in glycerol: A versatile catalytic system for C-X bond formation and hydrogenation processes
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Palladium nanoparticles stabilised by tris(3-sulfophenyl)phosphine trisodium salt in neat glycerol have been synthesised and fully characterised, starting from both Pd(II) and Pd(0) species. The versatility of this innovative catalytic colloidal solution has been proved by its efficient application in C-X bond formation processes (X=C, N, P, S) and C-C multiple bond hydrogenation reactions. The catalytic glycerol phase could be recycled more than ten times, preserving its activity and selectivity. The scope of each of these processes has demonstrated the power of the as-prepared catalyst, isolating the corresponding expected products in yields higher than 90%. The dual catalytic behaviour of this glycerol phase, associated to the metallic nanocatalysts used in wet medium (molecular- and surface-like behaviour), has allowed attractive applications in one-pot multi-step transformations catalysed by palladium, such as C-C coupling followed by hydrogenation, without isolation of intermediates using only one catalytic precursor. Copyright
- Chahdoura, Faouzi,Pradel, Christian,Gomez, Montserrat
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supporting information
p. 3648 - 3660
(2014/01/06)
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- Chemo/regioselective Aza-Michael additions of amines to conjugate alkenes catalyzed by polystyrene-supported AlCl3
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A simple and efficient procedure is presented for Aza-Michael additions of various amines with conjugate alkenes bearing electron withdrawing group catalyzed by polystyrene-supported aluminum chloride (Ps-AlCl3) without the use of any solvents. The catalyst shows high catalytic activity for both aromatic amines and aliphatic amines. Chemoselective additions of the two types of amines with conjugate alkenes are achieved. Regioselective additions of two different amino groups in one molecule proceed smoothly. Ps-AlCl 3 has better recyclability and can be reused several times without apparent loss of activity.
- Dai, Liyan,Zhang, Yi,Dou, Qianqian,Wang, Xiaozhong,Chen, Yingqi
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p. 1712 - 1716
(2013/03/13)
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- Selective and nonselective aza-michael additions catalyzed by a chiral zirconium bis-diketiminate complex
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Reaction of the chiral bis-diketiminate complex rac- or (R,R)-C 6H10(nacnacXyl)2ZrCl2 with AgOTf yielded the corresponding bis-triflate complex. The complex geometry changes from distorted octahedral in the dichloride complex to a pseudotetrahedral coordination involving π coordination of the diketiminate ligands. The bis-triflate complex is highly active for aza-Michael additions with turnover frequencies of 20000/h for the addition of morpholine to acrylonitrile and 1000/h for the addition of morpholine to methacrylonitrile. The enantioselectivities of the latter reaction in various solvents were low, never surpassing 19% ee. The reaction is first-order in olefin concentration and second order in amine concentration, which is explained by its participation as a base in the reaction mechanism. The presence of catalytic amounts of triethylamine slightly increases the observed rate constants and reduces the reaction order in amine to first order. Other activated alkenes such as methacrylonitrile, crotonitrile, methyl acrylate, and cyclohexenone can be employed, but no reactivity is observed toward styrene or vinyl ethers. Primary amines, secondary amines, and anilines can be employed as nucleophiles with activities correlating with their nucleophilicity, but the catalyst is unstable in the presence of alcohols.
- El-Zoghbi, Ibrahim,Kebdani, Myriam,Whitehorne, Todd J. J.,Schaper, Frank
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p. 6986 - 6995
(2014/01/06)
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- Synthesis and biological activity of substituted 2,4-diaminopyrimidines that inhibit Bacillus anthracis
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A series of substituted 2,4-diaminopyrimidines 1 has been prepared and evaluated for activity against Bacillus anthracis using previously reported (±)-3-{5-[(2,4-diamino-5-pyrimidinyl)methyl]-2,3-dimethoxyphenyl} -1-(1-propyl-2(1H)-phthalazinyl)-2-propen-1-one (1a), with a minimum inhibitory concentration (MIC) value of 1-3 μg/mL, as the standard. In the current work, the corresponding isobutenyl (1e) and phenyl (1h) derivatives displayed the most significant activity in terms of the lowest MICs with values of 0.5 μg/mL and 0.375-1.5 μg/mL, respectively. It is likely that the S isomers of 1 will bind the substrate-binding pocket of dihydrofolate reductase (DHFR) as in B. anthracis was found for (S)-1a. The final step in the convergent synthesis of target systems 1 from (±)-1-(1-substituted-2(1H)- phthalazinyl)-2-propen-1-ones 6 with 2,4-diamino-5-(5-iodo-3,4-dimethoxybenzyl) pyrimidine (13) was accomplished via a novel Heck coupling reaction under sealed-tube conditions.
- Nammalwar, Baskar,Bunce, Richard A.,Berlin, K. Darrell,Bourne, Christina R.,Bourne, Philip C.,Barrow, Esther W.,Barrow, William W.
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experimental part
p. 387 - 396
(2012/10/08)
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- Ultrasound-assisted aza-Michael reaction in water: A green procedure
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The conjugate addition of amines to conjugated alkenes (commonly known as aza-Michael reaction) constitutes a key step for the synthesis of various complex natural products, antibiotics, α-amino alcohols and chiral auxiliaries. Ultrasound-induced addition of several amines to α, β-unsaturated ketones, esters and nitriles has been carried out very efficiently in water as well as under solvent-free conditions. No catalysts or solid supports have been used in this method. Remarkable enhancement of reaction rate has been observed in water under ultrasound-induced method. This environmentally benign procedure has provided clean formation of the products with better selectivity.
- Bandyopadhyay, Debasish,Mukherjee, Sanghamitra,Turrubiartes, Luis C.,Banik, Bimal K.
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experimental part
p. 969 - 973
(2012/05/20)
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- Ecofriendly and efficient procedure for hetero-Michael addition reactions with an acidic ionic liquid as catalyst and reaction medium
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1-Methylimidazolium trifluoroacetate ([Hmim]-TFA) is reported as a cost-effective catalyst for a simple and environmentally benign hetero-Michael reaction. [Hmim]TFA works both as reaction medium and catalyst. The reaction is applicable to various aromatic sulfur and nitrogen nucleophiles. This method has advantages such as high yields, short reaction time, and simple workup. The catalyst could be recycled several times without any loss of activity.
- Dabiri, Minoo,Salehi, Peyman,Bahramnejad, Mahboobeh,Baghbanzadeh, Mostafa
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experimental part
p. 109 - 112
(2012/06/30)
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- Guanidine-based task-specific ionic liquids as catalysts for aza-Michael addition under solvent-free conditions
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An efficient and facile protocol for aza-Michael addition of aliphatic and aromatic amines to electron-deficit alkenes using [TMG][Lac] as catalyst under solvent-free conditions was established.
- Ying, Anguo,Zheng, Ming,Xu, Haidan,Qiu, Fangli,Ge, Changhua
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experimental part
p. 883 - 890
(2012/04/17)
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- Aza-Michael reactions in water using functionalized ionic liquids as the recyclable catalysts
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Some recyclable SO3H-functionalized ionic liquids have been used as catalysts in water for the aza-Michael reactions of amines with α,β-unsaturated compounds to produce β-amino compounds. High yields of the products, short reaction times, mild reaction conditions, simple experimental procedure, reusable catalysts and no obvious loss of the catalytic activity make this protocol a contribution to organic chemistry.
- Liu,Lu,Gu,Lu
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experimental part
p. 775 - 781
(2012/06/18)
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- Cesium fluoride catalyzed Aza-Michael addition reaction in aqueous media
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A green approach to the Aza-Michael addition reaction between an amine and α,β-unsaturated compounds has been achieved by conventional as well as non-conventional methods. The reaction is catalyzed by cesium fluoride (CsF) in aqueous media at ambient temperature to afford the product in excellent yield. Ultrasound irradiation has been used as a non-conventional energy source, which reduces the reaction time with improved product yield.
- Labade, Vilas B.,Pawar, Shivaji S.,Shingare, Murlidhar S.
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experimental part
p. 1055 - 1059
(2012/07/27)
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- Complex containing a Lewis acid and Bronsted acid for the catalytic reactions of aza-Michael addition
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The novel efficient complex catalyst containing a Lewis acid and a Bronsted acid have been prepared by the reaction of proline ion liquid and cuprous iodide. The catalyst was characterized by FT-IR techniques using pyridine as probe molecule. A fast, mild, and quantitative procedure for aza-Michael addition reactions between various amines and α,β- unsaturated carbonyl compounds and nitriles has been developed using the novel complex catalyst. The results showed that the novel catalyst owned high activities for the reactions with excellent yields within 1 min.
- Mao, Xin-Xin,Wang, Jiao,Xia, Qun-Hua,Shen, Yong-Miao
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experimental part
p. 525 - 528
(2011/10/31)
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- Hydroamination and alcoholysis of acrylonitrile promoted by the pincer complex {κP,κC,κP-2,6- (Ph2PO)2C6H3}Ni(OSO 2CF3)
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This report describes the catalytic activity of the pincer-type complex {κP,κC,κP-2,6-(Ph 2PO)2C6H3}Ni(OSO2CF 3) (1) in the anti-Markovnikov addition of aliphatic and aromatic amines and alcohols to acrylonitrile, crotonitrile, and methacrylonitrile. The influence of additives on the catalytic activities was investigated, and it was found that substoichiometric quantities of water promoted the C-N bond forming reactions catalyzed by 1, especially the reactions involving aromatic amines; in comparison, NEt3 had a less dramatic impact. The opposite pattern was observed for the alcoholysis of acrylonitrile promoted by 1: water had no beneficial effect on these reactions, while NEt3 proved to be a potent promoter. Another important difference between these reactions is that hydroamination works better with more nucleophilic amines, whereas the alcoholysis reactions work well with ArOH, CF3CH2OH, and ArCH2OH but not at all with the more nucleophilic aliphatic alcohols methanol, ethanol, and 2-propanol. Both hydroamination and alcoholysis proceed much better with acrylonitrile in comparison to its Me-substituted derivatives crotonitrile and methacrylonitrile. Under optimized conditions, precatalyst 1 promotes conjugate additions to acrylonitrile with catalytic turnover numbers of up to 100 (hydroamination) or higher (alcoholysis). Spectroscopic studies have established that the main Ni-containing species in the hydroamination reactions is a cationic adduct in which the olefinic substrate is bound to the Ni center via its nitrile moiety; this binding activates the double bond toward an outer-sphere nucleophilic attack by the amine (Michael addition). The solid-state structures of the cationic nitrile adducts [{κP, κC,κP-2,6-(Ph2PO)2C 6H3}Ni(NCR)][OSO2CF3] (R = Me (2a), CH2CH2N(H)Ph (2e)), which can be regarded as model complexes for the species involved in the hydroamination catalysis, have been elucidated. Also reported are the solid-state structures of the charge-neutral compound {κP,κC,κP-2,6-(i- Pr2PO)2C6H3}Ni(OSO 2CF3) and an octahedral Ni(II) species resulting from the aerobic/hydrolytic oxidation of 1.
- Salah, Abderrahmen B.,Offenstein, Caroline,Zargarian, Davit
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experimental part
p. 5352 - 5364
(2011/12/13)
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- Synthesis of a novel ionic liquid with both Lewis and Br?nsted acid sites and its catalytic activities
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The novel ionic liquid with both Lewis and Br?nsted acid sites has been synthesized and its catalytic activities for acetalization and Michael addition were investigated carefully. The novel ionic liquid was stable to water and could be used in aqueous solution. Furthermore, the molar ratio of the Lewis and Br?nsted acid sites could be adjusted according to different reactions. The results showed that the novel ionic liquid was very efficient for the traditional acid-catalyzed reactions with good to excellent yields in short time.
- Liang, Xuezheng,Qi, Chenze
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experimental part
p. 808 - 812
(2012/01/04)
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- Microwave-induced aza-michael reaction in water: A remarkably simple procedure
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Microwave-induced fast addition of several amines to conjugated carbonyl compounds has been carried out in water very efficiently in the absence of any catalyst. Copyright
- Kall, Andrea,Bandyopadhyay, Debasish,Banik, Bimal K.
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experimental part
p. 1730 - 1735
(2010/07/14)
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- Aqueous aza-michael reaction of conjugated alkenes: Toward spermine
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An aqueous aza-Michael reaction is efficiently achieved with excellent conversions without any additives. The method works very well on a molar scale with selectively for aliphatic amines. An intermediate for spermine is also made by this green process.
- Joshi, Jigar H.,Saiyed, Akeel S.,Bedekar, Ashutosh V.
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experimental part
p. 2857 - 2863
(2010/11/18)
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- An effective aza-michael addition of aromatic amines to electron-deficient alkenes in alkaline Al2O3
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Aza-Michael addition of aromatic or aliphatic amines with various electron-deficient alkenes was performed using alkaline Al2O 3 as solid media at room temperature afforded the corresponding Michael addition products in good to excellent yields.The alkaline Al 2O3 can be easily recovered and reused.
- Ai, Xin,Wang, Xin,Liu, Jin-Ming,Ge, Ze-Mei,Cheng, Tie-Ming,Li, Run-Tao
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experimental part
p. 5373 - 5377
(2010/08/06)
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- Novel efficient procedure for the conjugate addition of amines to electron deficient alkenes
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The novel efficient procedure has been developed for the conjugate addition of amines to electron deficient alkenes using the novel SO3H functionalized ionic liquid as catalyst. The results showed that the novel catalyst owned high activities for the reactions with excellent yields within several minutes. Various amines and electron deficient alkenes were successfully transformed to the corresponding products in the catalytic system. Operational simplicity, without need of any solvent, low cost of the catalyst used, room temperature, high yields, reusability, excellent chemoselectivity and wide applicability are the key features of this methodology.
- Sun, Xudong,Du, Yijun,Li, Chunqing,Qi, Chenze
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experimental part
p. 653 - 656
(2011/02/16)
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- A comparison between nickel and palladium precatalysts of 1,2,4-triazole based N-heterocyclic carbenes in hydroamination of activated olefins
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A comparison is drawn between the nickel and palladium precatalysts of 1,2,4-triazole based N-heterocyclic carbenes in the hydroamination of activated olefins. Though all of the newly designed nickel and palladium precatalysts, trans-[1-i-propyl-4-R-1,2,4-triazol-5-ylidene]2MBr2 [R = Et, M = Ni (1b); R = Et, M = Pd (1c); R = CH2CHCH2, M = Ni (2b) and R = CH2CHCH2, M = Pd (2c)], are moderately active for hydroamination reaction of a variety of secondary amines viz. morpholine, piperidine, pyrrolidine and diethylamine with activated olefins like, acrylonitrile, methyl acrylate, ethyl acrylate and t-butyl acrylate at room temperature in 1 hour, the nickel complexes (1b and 2b) exhibited superior activity compared to its palladium counterparts (1c and 2c). The better performance of the nickel complexes has been correlated to the more electron deficient metal center in the nickel 1b and 2b complexes than in the palladium 1c and 2c analogs based on the density functional theory studies. The 1b-c and 2b-c complexes were synthesized by the reaction of 1-i-propyl-4-R-1,2,4- triazolium bromide [R = Et (1a) and R = CH2CHCH2 (2a)] with MCl2 [M = Ni, Pd] in presence of NEt3 as a base. The Royal Society of Chemistry 2010.
- Dash, Chandrakanta,Shaikh, Mobin M.,Butcher, Ray J.,Ghosh, Prasenjit
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experimental part
p. 2515 - 2524
(2010/05/14)
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- POSITIVE RESIST COMPOSITION AND PATTERNING PROCESS
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A positive resist composition comprises (A) a resin component which becomes soluble in an alkaline developer under the action of an acid and (B) an acid generator. The resin (A) is a polymer comprising recurring units containing a non-leaving hydroxyl group represented by formula (1) wherein R1 is H, methyl or trifluoromethyl, X is a single bond or methylene, m is 1 or 2, and the hydroxyl group attaches to a secondary carbon atom. The composition is improved in resolution when processed by lithography.
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- Microwave-assisted, rapid, solvent-free aza-michael reaction by perchloric acid impregnated on silica gel
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Highly efficient solvent-free aza-Michael additions of a variety of amines to,-unsaturated carbonyl compounds under microwave-irradiation conditions catalyzed by perchloric acid impregnated on silica gel (HClO4/SiO2) is reported. The reactions are completed within 2-7min in a microwave oven to produce the corresponding adducts in excellent yields, and the catalyst can be recovered and reused.
- Singh, Surya Prakash,Kumar, T. Vijaya,Chandrasekharam,Giribabu,Reddy, P. Yella
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experimental part
p. 3982 - 3989
(2009/12/24)
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- Iodine-alumina catalyzed Aza- michael addition under solvent free conditions
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An efficient aza-Michael addition of amines to a variety of activated olefins was carried out under solvent free conditions using iodine-alumina as a catalyst at room temperature or under microwave irradiation (in case of solid) in high yield. 2009 Bentham Science Publishers Ltd.
- Saikia, Monmi,Kakati, Dwipen,Joseph, Maria Stalin,Sarma, Jadab Chandra
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experimental part
p. 654 - 658
(2010/06/15)
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- An efficient ZrCl4 catalyzed aza-michael addition reaction: Synthesis of C-linked carbo β3-amino acids
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A mild aza-Michael protocol has been developed using ZrCl4 as catalyst on α, β-unsaturated esters and nitriles. The aromatic amines were found to give the products with ease. The ZrCl4 mediated route was compatible with acid sensitive carbohydrate esters and provided an efficient method to prepare C-linked carbo β3-amino acids (β3-Caa).
- Damera, Krishna,Reddy, Katta L.,Sharma, Gangavaram V.M.
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experimental part
p. 151 - 155
(2010/04/23)
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- Aza-Michael addition of aliphatic or aromatic amines to α,β-unsaturated compounds catalyzed by a DBU-derived ionic liquid under solvent-free conditions
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A task-specific ionic liquid, 1,8-diazabicyclo[5.4.0]-undec-7-en-8-ium acetate has been successfully used as a catalyst for aza-conjugate addition of aliphatic or aromatic amines to various electron deficient alkenes under solvent-free conditions and at room temperature. The catalyst can be reused for six times without noticeable loss of activity.
- Ying, An-Guo,Liu, Luo,Wu, Guo-Feng,Chen, Gang,Chen, Xin-Zhi,Ye, Wei-Dong
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experimental part
p. 1653 - 1657
(2009/06/28)
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- Highly efficient Michael addition reaction of amines catalyzed by silica-supported aluminum chloride
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Aliphatic and aromatic amines undergo smooth nucleophilic addition to α,β-unsaturated compounds in the presence of a catalytic amount of silica-supported aluminum chloride at 60°C and under solvent-free conditions to produce the corresponding β-amino compounds in excellent yields. This method is simple and convenient and works efficiently under mild conditions. This catalyst can used again without losing its activity three times. Copyright Taylor & Francis Group, LLC.
- Saidi, Mohammad R.,Pourshojaei, Yaghoub,Aryanasab, Fezzeh
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experimental part
p. 1109 - 1119
(2009/09/08)
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- Nanocrystalline copper(II) oxide catalyzed aza-Michael reaction and insertion of α-diazo compounds into N-H bonds of amines
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Nanocrystalline copper(II) oxide efficiently catalyzed the conjugate addition of aliphatic amines to α,β-unsaturated compounds to produce β-amino compounds with excellent yields under mild reaction conditions. Similarly, Glycine esters are obtained in good yields by the insertion of α-diazoacetate into N-H bonds of amines. The catalyst is used for three cycles with minimal loss of activity.
- Kantam, M. Lakshmi,Laha, Soumi,Yadav, Jagjit,Jha, Shailendra
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experimental part
p. 4467 - 4469
(2009/12/01)
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- Asymmetric hydroamination of acrylonitrile derivatives catalyzed by Ni(II)-complexes
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Chiral ferrocenyl tridentate phosphine ligands were synthesized and used in asymmetric hydroamination reactions catalyzed by Ni(II)-complexes. Compounds of the type [Ni(PPP)L]2+, where L is a chloride, solvent molecule or a coordinated substrate, were isolated. The efficiency of these complexes in asymmetric catalysis was high when aliphatic or aromatic amines were reacted with electron-poor olefins, especially with acrylonitrile derivatives. This hydroamination reaction affords up to 95% enantioselectivity at -80 °C for the addition of morpholine to methacrylonitrile (69% ee at room temperature).
- Fadini, Luca,Togni, Antonio
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experimental part
p. 2555 - 2562
(2009/04/06)
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- Vanadyl(IV) acetate: An efficient, reusable heterogenous catalyst for Aza-Michael reaction under solvent-free conditions
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Vanadyl(IV) acetate [VO(OAc)2] efficiently catalyzes the conjugate addition of aliphatic, aromatic amines to α,β-unsaturated carbonyl compounds in solvent-free media at room temperature to afford corresponding amino compounds in good to excellent yields. The catalyst can be recovered and reused for further cycles. Copyright Taylor & Francis Group, LLC.
- Trivedi, Rajiv,Lalitha,Roy, Sarabindu
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p. 3556 - 3566
(2008/12/23)
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- Triethylammonium acetate (TEAA): A recyclable inexpensive ionic liquid promotes the chemoselective aza- and thia-Michael reactions
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A new, highly efficient, inexpensive, recyclable, mild, convenient, and green protocol for chemoselective aza/thia-Michael addition reactions of amines/thiols to α,β-unsaturated compounds using triethylammonium acetate (TEAA) ionic liquid was developed. The catalyst can be recycled ten times and obviate the need for toxic and expensive catalysts.
- Verma, Akhilesh K.,Attri, Pankaj,Chopra, Varun,Tiwari, Rakesh K.,Chandra, Ramesh
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experimental part
p. 1041 - 1047
(2009/11/30)
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- N-donor ligand as catalyst: A simple Aza-Michael addition reaction in aqueous media
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(Chemical Equation Presented) A novel approach for the Aza-Michael addition reactions between various amines and α,β-unsaturated esters, nitriles and ketones using N-donor Ligand catalyst (3 mol %) is described. The reactions are carried out in aqueous media at an ambient temperature to afford the products in excellent yields.
- Pawar, Shivaji S.,Dekhane, Deepak V.,Shingare, Murlidhar S.,Thore, Shivaji N.
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experimental part
p. 1869 - 1873
(2009/06/18)
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- Imidazolium-based polymer supported gadolinium triflate as a heterogeneous recyclable Lewis acid catalyst for Michael additions
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A heterogeneous Lewis acid catalytic system has been developed by incorporating gadolinium triflate on to poly[styrene-co-(1-((4-vinylphenyl)methyl)-3-methylimidazolium) tetrafluoroborate] (1-Gd(OTf)3), and the catalytic activity of this system has been examined for Michael additions of amines and thiols to α,β-unsaturated esters and acrylonitrile. The reactions proceed in moderate to excellent yields in the presence of catalytic system 1-Gd(OTf)3. The catalytic system could be efficiently recycled and reused.
- Alleti, Ramesh,Oh, Woon Su,Perambuduru, Meher,Ramana,Prakash Reddy
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p. 3466 - 3470
(2008/09/21)
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- A basic ionic liquid as catalyst and reaction medium: A rapid and simple procedure for Aza-Michael addition reactions
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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.
- Xu, Jian-Ming,Wu, Qi,Zhang, Qing-Yi,Zhang, Fu,Lin, Xian-Fu
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p. 1798 - 1802
(2008/02/08)
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- Bromodimethylsulfonium bromide mediated Michael addition of amines to electron deficient alkenes
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Bromodimethylsulfonium bromide has been found to be an efficient catalyst for the Michael addition of a wide variety of amines to electron deficient alkenes at room temperature. The protocol is very simple and chemoselective. Aliphatic and benzylic amines undergo conjugate addition within a very short period under solvent-free conditions and provide excellent yields of products.
- Khan, Abu T.,Parvin, Tasneem,Gazi, Sarifuddin,Choudhury, Lokman H.
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p. 3805 - 3808
(2008/02/06)
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- Significant rate acceleration of the aza-Michael reaction in water
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The addition of amines to conjugated alkenes has been carried out in water at room temperature very efficiently without any catalyst. Significant rate acceleration of this reaction is observed in water compared to organic solvents.
- Ranu, Brindaban C.,Banerjee, Subhash
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p. 141 - 143
(2007/10/03)
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