- 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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- 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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- 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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- Graphene oxide: An efficient and reusable carbocatalyst for aza-Michael addition of amines to activated alkenes
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Graphene oxide was found to be a highly efficient, reusable and cost-effective organocatalyst for the aza-Michael addition of amines to activated alkenes to furnish corresponding β-amino compounds in excellent yields. The Royal Society of Chemistry 2011.
- Verma, Sanny,Mungse, Harshal P.,Kumar, Neeraj,Choudhary, Shivani,Jain, Suman L.,Sain, Bir,Khatri, Om P.
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supporting information; experimental part
p. 12673 - 12675
(2012/01/05)
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- An efficient biomaterial supported bifunctional organocatalyst (ES-SO 3- C5H5NH+) for the synthesis of β-amino carbonyls
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A biomaterial supported organocatalyst, readily synthesized by the reaction of chemically modified sulfonic group containing expanded corn starch with pyridine exhibited excellent catalytic activity for the synthesis of β-amino carbonyls in excellent yields via aza-Michael addition of amines to electron deficient alkenes. A remarkable enhancement in the reaction rates was observed with the prepared bifunctional organocatalyst in comparison to the either starch grafted sulfonic acid or the corresponding homogeneous pyridinium p-toluenesulfonate.
- Verma, Sanny,Jain, Suman L.,Sain, Bir
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experimental part
p. 2314 - 2318
(2011/05/02)
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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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- 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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- Synthesis of novel deuterium labelled derivatives of N-alkylated polyamines
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Novel di-, tetra- and octadeuterated derivatives of mono-N-alkylated diaminopropanes, spermidines, spermines, symmetrically bis-N-alkylated spermines and unsymmetrically bis-N-alkylated spermines were synthesized. Deuterium labels were introduced into the RHNCH2CH2CN intermediate either by exchanging the protons next to the nitrile group under basic conditions with D2O-EtOD mixture or/and by reducing the nitrile group to a CD2-NH2 fragment with LiAlD4.
- H?kkinen, Merja R.,Kein?nen, Tuomo A.,Khomutov, Alex R.,Auriola, Seppo,Weisell, Janne,Alhonen, Leena,J?nne, Juhani,Veps?l?inen, Jouko
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experimental part
p. 547 - 562
(2009/04/07)
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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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- Tandem bis-aza-Michael addition reaction of amines in aqueous medium promoted by polystyrenesulfonic acid
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An efficient and environmentally benign tandem bis-aza-Michael addition of amines catalyzed by polystyrenesulfonic acid (PSSA) is described. This operationally simple high yielding microwave assisted synthetic protocol proceeded in water in the absence of any organic solvent.
- Polshettiwar, Vivek,Varma, Rajender S.
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p. 8735 - 8738
(2008/03/18)
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- Synthesis and antiplatelet activity of new imidazole-4-carboxylic acid derivatives
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1-Arylalkyl-5-phenylsulfonamino-imidazole-4-carboxylic acid esters and their carboxamides with an additional secondary amino group were synthesized and identified as antiplatelet agents in a low micromolar range (Born-test, inducer collagen). To describe the mechanism of action more precisely the Born-test was carried out as well with ADP, adrenaline or PAF, respectively. In addition, two compounds were investigated for their COX-1 inhibitory activities. Provided the essential structural criteria are met i.e. amide group or ester, sulfonylamino rest, hydrophobic moieties, and a secondary amino function, slight structural modifications are able to shift the pattern of activity among the above platelet receptors. So, the ester 5c exhibits PAF antagonistic activity at IC 50 = 1 μM and COX-1 inhibition (IC50 = 0.4 μM). The carboxamide 6c shows ADP antagonistic properties (IC50 = 2 μM). Compound 6g is as well PAF antagonistic (IC50 = 4 μM) and a COX-1 inhibitor (IC50 = 1 μM). The derivative 6i shows a strong antiadrenergic (IC50 = 0.15 μM) and PAF antagonistic (IC 50 = 0.66 μM) effect.
- Rehse, Klaus,Steege, Jens
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p. 539 - 547
(2007/10/03)
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- New highly selective inhibitors of class II fructose-1,6-bisphosphate aldolases
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Phosphoglycolo amidoxime and phosphoglycolo hydrazide, two new derivatives of phosphoglycolic acid, were synthesised and successfully tested as selective competitive inhibitors of class II FBP-aldolases.
- Fonvielle, Matthieu,Weber, Philippe,Dabkowska, Kasia,Therisod, Michel
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p. 2923 - 2926
(2007/10/03)
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- Sulfacytosine derivatives
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N1 -(1,2-dihydro-2-oxo-4-pyrimidinyl)sulfanilamides, bearing a lower alkyl, cycloalkyl or cycloalkyl-lower alkyl substituent in the 1-position, prepared by reaction of the corresponding 1-substituted-1,2-dihydro-2-oxo-4-aminopyrimidine and N-acylated sulfanilyl chloride with subsequent hydrolysis, are described. The end products are useful as antibacterial agents.
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