- β-Cyclodextrin promoted aza-Michael addition of amines to conjugated alkenes in water
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Highly efficient and environmentally benign aza-Michael additions of amines to α,β-unsaturated compounds catalyzed by β-cyclodextrin in water to produce the corresponding β-amino compounds in excellent yields under mild conditions are described. β-Cyclodextrin can be recovered and reused in subsequent reactions without loss of activity.
- Surendra,Krishnaveni, N. Srilakshmi,Sridhar,Rao, K. Rama
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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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- A catalytic method for room-temperature Michael additions using 12-tungstophosphoric acid as a reusable catalyst in water
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12-Tungstophosphoric acid (H3PW12O40) has been found to be an efficient and recyclable catalyst in promoting room temperature Michael additions of amines and aryl thiols to α,β- unsaturated esters and acrylonitrile in water to afford the corresponding saturated amines in good to excellent yields. Georg Thieme Verlag Stuttgart.
- Chen, Xiang,She, Jin,Shang, Zhicai,Wu, Jun,Zhang, Peizhi
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- Indium trichloride-catalyzed conjugate addition of amines to α,β-ethylenic compounds in water
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Catalytic amount of indium (III) trichloride efficiently catalyzed Michael reaction between amines and α,β-ethylenic compounds in water and under mild conditions. Indium trichloride can be recovered and reused without decrease in yield.
- Loh, Teck-Peng,Wei, Lin-Li
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- Air- and moisture-stable cationic (diphosphine)palladium(II) complexes as hydroamination catalysts X-ray crystal structures of two complexes
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A series of cationic (diphosphine)palladium(II) complexes have been prepared and fully characterized, including two crystal structures. These complexes were evaluated as catalysts for the hydroamination of acyclic alkenes. The reactivity of the catalysts is dependent on the nature of the diphosphine ligand and the substituents on the amine and alkene substrates.
- Li, Kelin,Horton, Peter N.,Hursthouse, Michael B.,Hii, King Kuok Mimi
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- Green synthesis of CuO nanoparticles using: Lantana camara flower extract and their potential catalytic activity towards the aza-Michael reaction
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Aza-Michael addition is one of the most exploited reactions in organic chemistry. It is regarded as one of the most popular and efficient methods for the creation of the carbon-nitrogen bond, which is a key feature of many bioactive molecules. Herein, we report the synthesis of CuO nanoparticles by an alkaline hydrolysis process in the presence of the flower extract of Lantana camara, an invasive weed, followed by calcination in air at 400 °C. Microscopic results indicated that the plant extract played an important role in the modulation of the size and shape of the product. In the presence of extract, porous CuO nanostructures are formed. While mostly aggregated rod-shaped CuO nanostructures are formed in the absence of extract. The products are pure and highly crystalline possessing the monoclinic phase. The CuO nanoparticles have been used as a catalyst in the aza-Michael addition reaction in aqueous medium under ultrasound vibration. The product yield is excellent and the catalyst is reusable up to the fifth cycle. The catalyst system can be extended to various substituted substrates with excellent to moderate yields.
- Chowdhury, Rakesh,Khan, Aslam,Rashid, Md. Harunar
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- Solid sodium stannate as a high-efficiency superbase catalyst for anti-Markovnikov hydroamination and hydroalkoxylation of electron-deficient olefins under mild conditions
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A solid superbase with H- above 26.5 has been obtained through thermal treatment of sodium stannate hydrate. It was found to be an efficient catalyst for anti-Markovnikov hydroamination and hydroalkoxylation of electron-deficient olefins under mild conditions.
- Zhang, Shuguo,Wei, Yudan,Yin, Shuangfeng,Au, Chak-Tong
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- Functionalized ionic liquid promoted aza-michael addition of aromatic amines
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A functionalized ionic liquid, 3-(N,N-dimethyldodecylammonium) propanesulfonic acid hydrogen sulphate ([DDPA][HSO4]) has been used as catalyst for the aza-Michael reactions of aromatic amines with α,β-unsaturated compounds at room temperature to produce β-amino compounds in good yields. The catalyst can be reused for several times without obvious loss of the catalytic activity.
- Liu, Xiao-Bing,Lu, Ming,Lu, Ting-Ting,Gu, Guo-Liang
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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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- Synthesis and Catalytic Application of Mixed Valence Iron (FeII/FeIII)-Based OMS-MIL-100(Fe) as an Efficient Green Catalyst for the aza-Michael Reaction
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Abstract: In the present study, open metal site iron-based MOF [MIL-100(Fe)], by a solvothermal method with polygonal morphology, are synthesised and then applied as a heterogeneous green catalyst for aza-Michael addition of various amines with α, β-unsaturated compounds. The MIL-100(Fe) was found to be efficient, selective, green and heterogeneous catalyst for the aza-Michael reaction. The proposed catalyst has better recyclability and can be reused six times without apparent loss of activity. Graphical Abstract: [Figure not available: see fulltext.].
- Rostamnia, Sadegh,Alamgholiloo, Hassan
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- Cyanoethylation of alcohols and amines by cesium-modified zeolite y
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Zeolite Y modified by cesium and magnesium ions was prepared by ion-exchange and impregnation methods, and its activity in the cyanoethylation of aliphatic and aromatic alcohols and amines was investigated. During the preparation of some samples, the transformation of zeolite Y into a pollucite-type phase occurred. This phase exhibited good activity in the cyanoethylation of aliphatic alcohols. The prepared solids modified by the impregnation method were more active than the ion-exchanged solids. The activities of the catalysts, in contrast to other basic solids, were scarcely affected by the presence of air or moisture. A correlation between catalyst basicity and catalytic activity is discussed. The catalysts were characterized by X-ray diffraction, volumetric nitrogen adsorption surface area measurement, and CO2 temperature-programmed desorption. Scanning electron microscopy revealed that the particles of the modified nanocatalysts were 40 nm. The reaction of acrylonitrile with linear alcohols in the presence of the catalysts was accelerated by microwave irradiation.
- Zamanian, Sara,Kharat, Ali Nemati
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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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- Synthesis of β-amino esters via aza-Michael addition of amines to alkenes promoted on silica: A useful and recyclable surface
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A solvent-free protocol for the synthesis of β-amino esters and nitriles has been developed via conjugate addition of amines to electron-deficient alkenes promoted on silica. The silica surface may be recycled. Both aliphatic and aromatic primary or secondary amines worked efficiently to yield the desired adducts in good to excellent yields.
- Basu, Basudeb,Das, Pralay,Hossain, Ismail
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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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- Polymer coated magnetically separable organocatalyst for C[sbnd]N bond formation via aza-Michael addition
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A polyacrylamide coated magnetite (PAM@MNP) catalyst was synthesized by following a two step approach involving the reaction of magnetite (Fe3O4) particles with coupling agent 3-(trimethoxysilyl)propyl methacrylate followed by grafting of acrylamide and subsequent polymerization via surface initiated radical polymerization technique. The synthesized organocatalyst was used for a one-pot aza-Michael addition reaction of amines with electron deficient alkenes to give β-amino carbonyls. The magnetic properties of the synthesized organocatalyst provide it a facile recovery by external magnet which eliminates the problems arising during catalyst separation by conventional filtration.
- Panwar, Vineeta,Ray, Siddharth S.,Jain, Suman L.
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- Anti-Markovnikov N-H and O-H additions to electron-deficient olefins catalyzed by well-defined Cu(I) anilido, ethoxide, and phenoxide systems
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The monomeric Cu(I) complexes (IPr)Cu(Z) (IPr = 1,3-bis(2,6-diisopropylphenyl)imidazol-2-ylidene, Z = NHPh, OEt, or OPh) react with YH (Y = PhNH, PhCH2NH, EtO, or PhO) to catalytically add Y-H bonds across the C=C bond of electron-deficient olefins to yield anti-Markovnikov organic products. Catalytic activity has been observed for olefins CH2C(H)(X) with X = CN, C(O)Me, or CO2Me as well as crotononitrile. Preliminary studies implicate an intermediate in which the C-Y bond forms through a nucleophilic addition pathway. Copyright
- Munro-Leighton, Colleen,Blue, Elizabeth D.,Gunnoe, T. Brent
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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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- LiClO4 accelerated Michael addition of amines to α,β-unsaturated olefins under solvent-free conditions
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Several primary and secondary amines were added to α,β- unsaturated esters, nitriles, amides, and ketones to give the corresponding saturated amines mediated by solid lithium perchlorate under solvent-free and environmentally friendly conditions at room temperature.
- Azizi, Najmedin,Saidi, Mohammad R.
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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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- METHOD FOR PRODUCING AROMATIC AMINE COMPOUNDS FROM PHENOLS
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PROBLEM TO BE SOLVED: To provide a method for producing an aromatic amine compound from phenols and amines with a high yield and a high selectivity, which includes ones subjected to polyfunctionalization, under relatively low temperature and relatively low pressure, without using an additive which gives a co-product having high environmental load. SOLUTION: Phenols and hydrogen are introduced into a first catalyst cartridge receiving a solid catalyst containing platinum group elements and continuously hydrogenated into cyclohexanones. The resultant cyclohexanones, along with amines selected from ammonia, primary amines and secondary amines, and hydrogen trapping agents are subsequently introduced into a second catalyst cartridge receiving a solid catalyst containing platinum group elements to continuously produce aromatic amine compounds by dehydration condensation and dehydrogenation with amines. SELECTED DRAWING: Figure 2 COPYRIGHT: (C)2021,JPOandINPIT
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Paragraph 0017; 0043
(2021/06/04)
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- Continuous Synthesis of Aryl Amines from Phenols Utilizing Integrated Packed-Bed Flow Systems
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Aryl amines are important pharmaceutical intermediates among other numerous applications. Herein, an environmentally benign route and novel approach to aryl amine synthesis using dehydrative amination of phenols with amines and styrene under continuous-flow conditions was developed. Inexpensive and readily available phenols were efficiently converted into the corresponding aryl amines, with small amounts of easily removable co-products (i.e., H2O and alkanes), in multistep continuous-flow reactors in the presence of heterogeneous Pd catalysts. The high product selectivity and functional-group tolerance of this method allowed aryl amines with diverse functional groups to be selectively obtained in high yields over a continuous operation time of one week.
- Ichitsuka, Tomohiro,Kobayashi, Shū,Koumura, Nagatoshi,Sato, Kazuhiko,Takahashi, Ikko
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p. 15891 - 15896
(2020/07/13)
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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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- 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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- On-water magnetic NiFe2O4 nanoparticle-catalyzed Michael additions of active methylene compounds, aromatic/aliphatic amines, alcohols and thiols to conjugated alkenes
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Here, we have demonstrated the Michael addition of active methylene compounds, aromatic/aliphatic amines, thiols and alcohols to conjugated alkenes using magnetic nano-NiFe2O4 as reusable catalyst in water. Nano-NiFe2O4 efficiently catalyzed the formation of C-C and C-X (X = N, S, O etc.) bond through 1,4-addition reactions.
- Payra, Soumen,Saha, Arijit,Banerjee, Subhash
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p. 95951 - 95956
(2016/10/25)
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- Copper-Catalyzed Aza-Michael Addition of Aromatic Amines or Aromatic Aza-Heterocycles to α,β-Unsaturated Olefins
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A highly efficient and mild Cu-catalyzed conjugate addition reaction of aromatic amines and aromatic aza-heterocycles to α,β-unsaturated olefins is described. The transformation is promoted by 3-7 mol % of a Cu complex generated in situ from a mixture of inexpensive CuCl, a readily available phosphine or imidazolium salt, and KOt-Bu at ambient temperature. A wide range of β-amino sulfone, β-amino nitrile, and β-amino carbonyl compounds is efficiently and selectively synthesized in high yields (62-99%).
- Kim, Seongcheol,Kang, Seongil,Kim, Gihyeon,Lee, Yunmi
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p. 4048 - 4057
(2016/06/09)
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- Aza-Michael mono-addition using acidic alumina under solventless conditions
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Aza-Michael reactions between primary aliphatic and aromatic amines and various Michael acceptors have been performed under environmentally-friendly solventless conditions using acidic alumina as a heterogeneous catalyst to selectively obtain the corresponding mono-adducts in high yields. Ethyl acrylate was the main acceptor used, although others such as acrylonitrile, methyl acrylate and acrylamide were also utilized successfully. Bi-functional amines also gave the mono-adducts in good to excellent yields. Such compounds can serve as intermediates for the synthesis of anti-cancer and antibiotic drugs.
- Bosica, Giovanna,Abdilla, Roderick
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- Synthesis, Characterization and Catalytic Application of MCM 41 Supported Phenanthrolinium Dibromide Catalyst for Aza-Michael Addition Reaction in Aqueous Medium
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Abstract: MCM-41 immobilized phenanthrolinium dibromide (phen-MCM-Br2) was easily prepared and applied as an efficient heterogeneous catalyst for aza-Michael addition of aromatic amines to α,β-unsaturated nitriles and nitro compounds in water. The catalyst was characterized by CHN, TGA, FT-IR, SEM, EDAX, XRD, BET, and TEM. It could be simply recovered and reused several times without significant loss of catalytic activity. Graphical Abstract: [Figure not available: see fulltext.]
- Hosseinzadeh, Rahman,Aghili, Nora,Tajbakhsh, Mahmood
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p. 1194 - 1203
(2016/07/06)
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- Pd(II)/Ag(I)-Promoted One-Pot Synthesis of Cyclic Ureas from (Hetero)Aromatic Amines and Isocyanates
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A simple and facile one-pot reaction has been developed to afford a diverse range of N,N′-disubstituted benzimidazolones and imidazopyridinones containing two differently substituted N atoms. A cooperative Pd(II)/Ag(I) system promotes the sequential addition/intramolecular C-H amidation reaction of (hetero)aromatic amines and isocyanates, leading to the formation of two C-N bonds. A mechanism involving radical intermediates generated by single-electron transfer (SET) in the presence of a Ag2CO3 oxidant and Pd(OAc)2 Lewis acid is proposed. This protocol offers an operationally easy, simple, and robust approach with the use of readily available starting materials, good functional group tolerance, and high efficiency.
- Youn, So Won,Kim, Yi Hyun
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supporting information
p. 6140 - 6143
(2016/12/09)
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- Gold nanoparticles on OMS-2 for heterogeneously catalyzed aerobic oxidative α,β-dehydrogenation of β-heteroatom-substituted ketones
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In the presence of Au nanoparticles supported on manganese oxide OMS-2 (Au/OMS-2), various kinds of β-heteroatom-substituted α,β-unsaturated ketones (heteroatom = N, O, S) can be synthesized through α,β-dehydrogenation of the corresponding saturated ketones using O2 (in air) as the oxidant. The catalysis of Au/OMS-2 is truly heterogeneous, and the catalyst can be reused.
- Yoshii, Daichi,Jin, Xiongjie,Yatabe, Takafumi,Hasegawa, Jun-ya,Yamaguchi, Kazuya,Mizuno, Noritaka
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supporting information
p. 14314 - 14317
(2016/12/14)
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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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- Aza-Michael reaction promoted by aqueous sodium carbonate solution
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A general and efficient aza-Michael reaction promoted by aqueous sodium carbonate solution has been developed. The reaction has complete mono-alkylation selectivity and proceeds with complete chirality retention for chiral amino esters. With a broad substrate scope, a well-common catalyst and simple operation, the catalytic approach provides a facile, practicable, economical, and environmentally benign method for the synthesis of β-amino carbonyl compounds.
- Tang, Xiao-Ji,Yan, Zhao-Lei,Chen, Wen-Liang,Gao, Ya-Ru,Mao, Shuai,Zhang, Yan-Lei,Wang, Yong-Qiang
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supporting information
p. 2669 - 2673
(2013/06/05)
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- Boric acid/glycerol as an efficient catalyst for synthesis of thiomorpholine 1,1-dioxide by double michael addition reaction in water
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Thiomorpholine 1,1-dioxides were prepared with double Michael addition reaction of aromatic amines to divinyl sulfone catalyzed by boric acid/glycerol in water. This catalyst system was also used for the Michael addition reaction of aromatic amines to electron-deficient alkenes. The reaction is simple and green and gives good to excellent yields.
- Halimehjnai, Azim Ziyaei,Hosseyni, Seyedmorteza,Gholami, Hadi,Hashemi, Mohammed M.
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p. 191 - 197,7
(2020/09/02)
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- O-benzenedisulfonimide as a reusable brnsted acid catalyst for hetero-michael reactions
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The hetero-Michael reactions among various oxygen, sulfur, and nitrogen nucleophiles and ,-unsaturated compounds were carried out in the presence of catalytic amounts of o-benzenedisulfonimide as Brnsted acid organocatalyst. The reaction conditions were very mild, and the yields of target products were good. The catalyst was easily recovered and purified, ready to be used in further reactions. This ability grants economic and ecological advantages. Supplemental materials are available for this article. Go to the publisher's online edition of Synthetic Communications to view the free supplemental file.
- Barbero, Margherita,Cadamuro, Silvano,Dughera, Stefano
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p. 758 - 767
(2013/01/15)
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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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- Hemilabile β-aminophosphine ligands derived from 1,3,5-triaza-7- phosphaadamantane: Application in aqueous ruthenium catalyzed nitrile hydration
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A series of β-aminophosphines derived from 1,3,5-triaza-7- phosphaadamantane (PTA) are described. PTA-CHPhNHPh (1), PTA-CH(p-C 6H4OCH3)NHPh (2), and PTA-CPh2NHPh (3) were prepared in good yield (62-77%) by reaction of lithiated PTA with the corresponding imine followed by hydrolysis. Compounds 1 and 2 were synthesized as pairs of diastereomers which were separated by successive recrystallization from THF/hexane. Compounds 1-3 are somewhat soluble in water (S 25o = 4.8 (1), 4.9 (2), 2.7 (3) g/L). Upon coordination to Ru(II) arene centers both monodentate (κ1-P) [RuCl 2(η6-toluene)(1-3)] and bidentate (κ 2-P,N) [RuCl(η6-toluene)(1-3)]Cl coordination modes were observed. Ru(II) arene complexes 4-6 exhibited hemilabile behavior transitioning between κ1-P and κ2-P,N coordination upon change in solvent or addition of a coordinating ligand such as Cl- or CH3CN. Complexes (4-6) were found to be active air stable catalysts for the aqueous phase hydration of various nitriles with TOF up to 285 h-1 and TON of up to 97 000 observed.
- Lee, Wei-Chih,Sears, Jeremiah M.,Enow, Raphel A.,Eads, Kelly,Krogstad, Donald A.,Frost, Brian J.
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supporting information
p. 1737 - 1746
(2013/03/29)
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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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- Lithium tetrafluoroborate catalyzed highly efficient inter- and intramolecular aza-Michael addition with aromatic amines
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Lithium tetrafluoroborate has been demonstrated for the first time to be an efficient catalyst in intermolecular aza-Michael addition aromatic amines to electron deficient alkenes. Suitability of the same catalyst in intramolecular aza-Michael addition leading 2-aryl-2,3-dihydroquinolin-4(1H) ones has also been described.
- Lad,Kulkarni,Desai,Wadgaonkar
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experimental part
p. 1059 - 1064
(2012/03/11)
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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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- 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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- 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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- 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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- Squaric acid as an impressive organocatalyst for Michael addition in water
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A simple, green, and environmentally benign protocol for squaric acid (5 mg) catalyst conjugate addition of aromatic amines and thiols to unsaturated carbonyl compounds in water in good to excellent yields is developed. The advantages of low sensitivity toward moisture and oxygen, high tolerance of different functional groups, green reaction media and efficient recyclability make this organocatalyst suitable for both laboratory and industrial scale synthesis of β-substituted carbonyls under very mild conditions.
- Azizi, Najmadin,Saki, Elham,Edrisi, Mahtab
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experimental part
p. 973 - 977
(2012/05/20)
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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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- Aza-michael addition of amines to α,β-unsaturated compounds using molecular iodine as catalyst
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Aza-Michael adducts are obtained in very good yields by the conjugate addition of aliphatic amines to α,β-unsaturated compounds using molecular iodine as catalyst in dichloromethane at room temperature. Aromatic amines were found to be reactive under reflux in toluene.
- Borah, Kalyan Jyoti,Phukan, Mridula,Borah, Ruli
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experimental part
p. 2830 - 2836
(2010/11/02)
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- Silicon tetrachloride catalyzed aza-michael addition of amines to conjugated alkenes under solvent-free conditions
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The efficient and very simple conjugate addition of aromatic and aliphatic amines to α,β-unsaturated carbonyl compounds under solvent-free conditions in the presence of catalytic amount of silicon tetrachloride is reported. The reaction of aryl and alkyl amines with different Michael acceptors gave the corresponding Michael adducts with simple catalyst and good to excellent yields. Georg Thieme Verlag Stuttgart New York.
- Azizi, Najmedin,Baghi, Roya,Ghafuri, Hossein,Bolourtchian, Mohammad,Hashemi, Mohammad
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experimental part
p. 379 - 382
(2010/04/03)
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- STABILIZATION OF HYDROXYLAMINE CONTAINING SOLUTIONS AND METHOD FOR THEIR PREPARATION
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The invention relates to the use of amidoximes for prevention of or stabilization of hydroxylamine compounds against undesired decomposition.
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Page/Page column 14
(2009/05/28)
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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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- 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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- Assessment and use of two silicon carbide multi-well plates for library synthesis and proteolytic digests using microwave heating
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The use of two silicon carbide plates is reported for the preparation of three libraries of organic molecules using microwave heating. In addition, a preliminary study has been carried out, showing that one of the plates can also be used in a proteomics setting. Both the 24-position and 48-position plates heated evenly when irradiated with microwave energy. The 48-position plate was used to prepare a library of N-aryl functionalized β-amino esters via an aza-Michael reaction between anilines and Michael acceptors. The 24-position plate was used to prepare a library of biaryls via a Suzuki coupling methodology and a library of 1,4-dihydropyridines via a Hantzsch synthesis. The 48-position plate was also used to perform the proteolytic digestion of insulin chain B by trypsin. The Royal Society of Chemistry 2009.
- Stencel, Lauren M.,Kormos, Chad M.,Avery, Keri B.,Leadbeater, Nicholas E.
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experimental part
p. 2452 - 2457
(2009/09/26)
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- Novel synthesis of 3-aminopropionitriles by ring opening of 2-oxazolidinones with cyanide ion
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Nucleophilic attack of cyanide ion on the 5-position of 2-oxazolidinones in the presence of 18-crown-6 gave 3-aminopropionitriles.
- Taniguchi, Tsuyoshi,Goto, Naoya,Ishibashi, Hiroyuki
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supporting information; experimental part
p. 4857 - 4858
(2009/10/26)
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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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- 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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- Fast, easy, solvent-free, microwave-promoted Michael addition of anilines to α,β-unsaturated alkenes: synthesis of N-aryl functionalized β-amino esters and acids
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The rapid, simple, microwave-promoted synthesis of N-aryl functionalized β-amino esters using Michael addition reactions is presented. Reactions are performed neat at 200 °C for 20 min and are catalyzed by acetic acid. The esters can be easily hydrolyzed to the corresponding N-aryl functionalized β-amino acids.
- Amore, Kristen M.,Leadbeater, Nicholas E.,Miller, Tyson A.,Schmink, Jason R.
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p. 8583 - 8586
(2007/10/03)
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- ZrOCl2·8H2O on montmorillonite K10 accelerated conjugate addition of amines to α,β-unsaturated alkenes under solvent-free conditions
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At room temperature, ZrOCl2·8H2O on montmorillonite K10 efficiently catalyzes conjugate addition of amines to a variety of conjugated alkenes such as α,β-unsaturated carbonyl compounds, carboxylic esters, nitriles and amides under solvent-free conditions. The catalyst can be recycled for subsequent reactions without any appreciable loss of efficiency.
- Hashemi, Mohammed M.,Eftekhari-Sis, Bagher,Abdollahifar, Amir,Khalili, Behzad
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p. 672 - 677
(2007/10/03)
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