- Switching Selectivity in Copper-Catalyzed Transfer Hydrogenation of Nitriles to Primary Amine-Boranes and Secondary Amines under Mild Conditions
-
A simple and efficient copper-catalyzed selective transfer hydrogenation of nitriles to primary amine-boranes and secondary amines with an oxazaborolidine-BH3 complex is reported. The selectivity control was achieved under mild conditions by switching the solvent and the copper catalysts. More than 30 primary amine-boranes and 40 secondary amines were synthesized via this strategy in high selectivity and yields of up to 95%. The strategy was applied to the synthesis of 15N labeled in 89% yield.
- Song, Hao,Xiao, Yao,Zhang, Zhuohua,Xiong, Wanjin,Wang, Ren,Guo, Liangcheng,Zhou, Taigang
-
p. 790 - 800
(2022/01/11)
-
- Reusable Co-nanoparticles for general and selectiveN-alkylation of amines and ammonia with alcohols
-
A general cobalt-catalyzedN-alkylation of amines with alcohols by borrowing hydrogen methodology to prepare different kinds of amines is reported. The optimal catalyst for this transformation is prepared by pyrolysis of a specific templated material, which is generatedin situby mixing cobalt salts, nitrogen ligands and colloidal silica, and subsequent removal of silica. Applying this novel Co-nanoparticle-based material, >100 primary, secondary, and tertiary amines includingN-methylamines and selected drug molecules were conveniently prepared starting from inexpensive and easily accessible alcohols and amines or ammonia.
- Beller, Matthias,Gawande, Manoj B.,Jagadeesh, Rajenahally V.,Kadam, Ravishankar G.,Li, Xinmin,Ma, Zhuang,Petr, Martin,Zbo?il, Radek,Zhou, Bei
-
p. 111 - 117
(2022/01/06)
-
- Nickel Complexes Bearing N,N,O-Tridentate Salicylaldiminato Ligand: Efficient Catalysts for Imines Formation via Dehydrogenative Coupling of Primary Alcohols with Amines
-
Treatment of salicylaldiminato ligand L1H-L2H (L1H = 2,4-di-tert-butyl-6-((quinolin-8-ylimino)methyl)phenol; L2H = 2,4-di-tert-butyl-6-(((2-(diethylamino)ethyl)imino)methyl)phenol) with Ni(OAc)2·4H2O in refluxing ethanol afforded nickel complexes [(L1)Ni(OAc)] (1) and [(L2)Ni(OAc)] (2), respectively. Reaction of L3H (L3H = (2,4-di-tert-butyl-6-(((2-(pyridin-2-yl)ethyl)imino)methyl)phenol)) with Ni(OAc)2·4H2O in the presence of excess triethylanmine gave the dual ligands coordinated nickel complex [(L2)2Ni] (3). Complexes 1-3 were well characterized by high-resolution mass spectrometry, infrared spectroscopy, elemental analysis, and X-ray diffraction analysis. All the three Ni(II) complexes exhibited efficient activity and good selectivity in the acceptorless dehydrogenative coupling of alcohols and amines to produce imines and diimines. The present protocol provides an atom-economical and sustainable route for the synthesis of various imine derivatives by employing an earth-abundant nickel salt and easily prepared salicylaldiminato ligands.
- Han, Zhangang,Hao, Zhiqiang,Lin, Jin,Lu, Guo-Liang,Zhang, Junhua,Zhang, Xiaoying
-
p. 3843 - 3853
(2021/11/18)
-
- Efficient One-Pot Reductive Aminations of Carbonyl Compounds with Aquivion-Fe as a Recyclable Catalyst and Sodium Borohydride
-
A one-pot reductive amination of aldehydes and ketones with NaBH4 was developed with a view to providing efficient, economical and greener synthetic conditions. A recyclable iron-based Lewis catalyst, Aquivion-Fe, was used to promote imine formation in cyclopentyl methyl ether, followed by the addition of a small amount of methanol to the reaction mixture to enable C=N reduction by NaBH4. The protocol, applied to a wide number of amines and carbonyl compounds, resulted in ever complete conversion of these latter with excellent chemoselectivity towards the expected amination products in the most cases. Isolated yields, determined for a selection of the screened substrates, were found consistent with the previously obtained conversion and selectivity data. Cinacalcet, an important active pharmaceutical ingredient, was efficiently prepared by the title procedure.
- Airoldi, Veronica,Piccolo, Oreste,Roda, Gabriella,Appiani, Rebecca,Bavo, Francesco,Tassini, Riccardo,Paganelli, Stefano,Arnoldi, Sebastiano,Pallavicini, Marco,Bolchi, Cristiano
-
p. 162 - 168
(2019/12/11)
-
- One-pot, chemoselective synthesis of secondary amines from aryl nitriles using a PdPt-Fe3O4nanoparticle catalyst
-
We have developed a new catalytic method for the one-pot, cascade synthesis of unsymmetrical secondary amines via the reductive amination of aryl nitriles with nitroalkanes using a PdPt-Fe3O4 nanoparticle (NP) catalyst. The use of a bimetallic catalyst resulted in enhanced reactivity and selectivity compared to that of either monometallic Pd-Fe3O4 or the Pt-Fe3O4 NP catalyst. Using this bimetallic catalytic system, we were successful in the synthesis of various unsymmetrical secondary amines under mild conditions. However, aryl nitriles containing an electron-donating substituent were rather resistant to the reductive amination, and when hexafluoroisopropanol (HFIP) was used as a co-solvent, the reaction selectivity and yield for unsymmetrical secondary amines increased dramatically. Using the catalyst system, one-pot, gram-scale synthesis of indole was possible from 2-nitrophenylacetonitrile. Due to the magnetic property of the Fe3O4 support, the bimetallic catalyst could easily be recycled using an external magnet at least four times.
- Byun, Sangmoon,Cho, Ahra,Cho, Jin Hee,Kim, B. Moon
-
p. 4201 - 4209
(2020/09/23)
-
- Efficient photocatalytic one-pot hydrogenation and N-alkylation of nitrobenzenes/benzonitriles with alcohols over Pd/MOFs: Effect of the crystal morphology & “quasi-MOF” structure
-
One-pot multi-step reactions over visible-light induced catalysis feature the sustainable green process. Here, ligand structure change and 2-MI coordinated modulation were adapted to adjust the crystal size, morphology and crystalline structure of Fe-MOFs; double solvent impregnation was employed for the Pd loading; “quasi-MOF” materials with retained morphology were formed with calcination under N2. Above modified materials were employed as multifunctional photocatalysts for highly efficient one-pot hydrogenation and N-alkylation of nitrobenzenes or benzonitriles with alcohols after in situ Pd photoreduction. Photocatalytic performance was evidently affected by the Fe-MOFs crystal size, morphology, crystalline structure alteration and “quasi-MOF” construction. One-pot hydrogenation and N-alkylation of benzonitriles with alcohols was achieved with excellent catalytic performance firstly in heteroegeneous catalysis. Reaction mechanism was proposed with the assistance of in situ DRIFTS.
- Bian, Fengxia,Cheng, Hongmei,Jiang, Heyan,Liu, Xingyan,Long, Xingyu,Yang, Chaofen
-
p. 121 - 131
(2020/06/23)
-
- Ultra-small cobalt nanoparticles from molecularly-defined Co-salen complexes for catalytic synthesis of amines
-
We report the synthesis of in situ generated cobalt nanoparticles from molecularly defined complexes as efficient and selective catalysts for reductive amination reactions. In the presence of ammonia and hydrogen, cobalt-salen complexes such as cobalt(ii)-N,N′-bis(salicylidene)-1,2-phenylenediamine produce ultra-small (2-4 nm) cobalt-nanoparticles embedded in a carbon-nitrogen framework. The resulting materials constitute stable, reusable and magnetically separable catalysts, which enable the synthesis of linear and branched benzylic, heterocyclic and aliphatic primary amines from carbonyl compounds and ammonia. The isolated nanoparticles also represent excellent catalysts for the synthesis of primary, secondary as well as tertiary amines including biologically relevant N-methyl amines.
- Beller, Matthias,Chandrashekhar, Vishwas G.,Gawande, Manoj B.,Jagadeesh, Rajenahally V.,Kalevaru, Narayana V.,Kamer, Paul C. J.,Senthamarai, Thirusangumurugan,Zbo?il, Radek
-
p. 2973 - 2981
(2020/03/27)
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- HYDROGENATION OF IMINES WITH RU COMPLEXES
-
The present invention relates to the field of catalytic hydrogenation and to the use of ruthenium complexes having a bidentate diphosphine ligand or two monodentate phosphine ligands, two carboxylate ligands and optionally a diamine ligand in hydrogenatio
- -
-
Page/Page column 33-34; 36-38
(2019/09/18)
-
- Synthesis and evaluation of Zn(II) dithiocarbamate complexes as potential antibacterial, antibiofilm, and antitumor agents
-
Four complexes having the formula [Zn(L)2] [L1 = (C18H20NS2 –), N-(4-isopropyl-benzyl)-(benzyl)-dithiocarbamate], [L2 = (C10H12NS2 –), N-(benzyl)-(ethyl)-dithiocarbamate], [L3 = (C19H22ONS2 –), N-(4-isopropyl-benzyl)-(4-methoxy-benzyl)-dithiocarbamate], and [L4 = (C16H16NS2 –), N-(benzyl)-(4-methyl-benzyl)-dithiocarbamate] have been contemplated, synthesized, and characterized by elemental analysis and IR, 1H, 13C NMR and UV–visible absorption spectra. All Zn(II) complexes have similar geometry and coordination number. Complex A2 (with ligand L2) crystallizes in triclinic system with space group P-1 having distorted square pyramidal geometry which was stabilized by weak C–H···π and C–H···S intramolecular interactions. The antibacterial, antibiofilm, and antitumor activities of the complexes have been screened and A2 and A3 showed their prominence. Interestingly, both A2 and A3 showed more killing potential against multi-drug resistant gram-positive isolates with MIC indices of 16 μg mL?1 and 16 μg mL?1, respectively, against both MRSA and MSSA, while the antitumor agent A3 showed its prominence with GI50 and LC50 41.15 and 133.73 μg mL?1, respectively.
- Maurya, Vinay Kumar,Singh, Ashish Kumar,Singh, Ravi Pratap,Yadav, Shivangi,Kumar, Krishna,Prakash, Pradyot,Prasad, Lal Bahadur
-
p. 3338 - 3358
(2019/11/26)
-
- Mesoporous cobalt/manganese oxide: A highly selective bifunctional catalyst for amine-imine transformations
-
Herein, we discuss a heterogeneous catalytic protocol using cobalt doped mesoporous manganese oxide for amine-alcohol cross-coupling to selectively produce symmetric or asymmetric imines. Thorough investigations on the surface chemistry and physical properties of the material revealed its outstanding oxidation-reduction properties and reaction mechanism which was supported by quantum mechanical calculations done by using density functional theory (DFT).
- Dutta, Biswanath,March, Seth,Achola, Laura,Sahoo, Sanjubala,He, Junkai,Shirazi Amin, Alireza,Wu, Yang,Poges, Shannon,Pamir Alpay,Suib, Steven L.
-
p. 3180 - 3185
(2018/07/29)
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- Preparation of the Ru3(CO)8-pyridine-alcohol cluster and its use for the selective catalytic transformation of primary to secondary amines
-
The synthesis of pyridine alcohol based ruthenium carbonyl clusters Ru3(hep)2(CO)8 (1), Ru3(hpp)2(CO)8 (2), and Ru3(bhmp-H)2(CO)8 (3) {hep-H = 2-(2-hydroxyethyl)pyridine, hpp-H = 2-(3-hydroxypropyl)pyridine and bhmp-H2 = 2,6-bis(hydroxymethyl)pyridine} has been carried out by the reaction of the corresponding pyridine-alcohol ligands with Ru3(CO)12. Clusters 1-3 have been characterized using elemental analysis, NMR, FT-IR, mass spectrometry and single-crystal X-ray structures. The clusters were explored for the selective catalytic transformation of primary amines into secondary amines using alcohols as the mono-alkylating agents via hydrogen transfer reactions. All three display efficient catalytic activity with 1 being the most effective.
- Singh, Ajeet,Mobin, Shaikh M.,Mathur, Pradeep
-
p. 14033 - 14040
(2018/11/23)
-
- Simple Metal-Free Direct Reductive Amination Using Hydrosilatrane to Form Secondary and Tertiary Amines
-
This work describes the use of cheap, safe, and easy-to-handle hydrosilatrane as the reductant in direct reductive amination reactions. This efficient method enables a facile, metal-free access to secondary and tertiary amines from a wide range of aldehydes and ketones, with the synthesis of tertiary amines requiring no additives at all. This reaction demonstrates excellent functional group tolerance, chemoselectivity, and scalability. (Figure presented.).
- Varjosaari, Sami E.,Skrypai, Vladislav,Suating, Paolo,Hurley, Joseph J. M.,Lio, Ashley M. De,Gilbert, Thomas M.,Adler, Marc J.
-
supporting information
p. 1872 - 1878
(2017/06/09)
-
- Selective Activation of Alcohols in the Presence of Reactive Amines over Intermetallic PdZn: Efficient Catalysis for Alcohol-Based N-Alkylation of Various Amines
-
Pd-based intermetallic compounds supported on Al2O3 (PdxMy/Al2O3, where M = Bi, Cu, Fe, Ga, In, Pb, Sn, or Zn) were prepared and tested as catalysts for the selective activation of alcohols in the presence of reactive amines, which is highly challenging and is the key strategy for alcohol-based N-alkylation of amines. Although the Pd/Al2O3 catalyst exhibited a high catalytic activity, undesired side reactions such as amine dimerization (via amine activation) and C-O bond scission occurred, resulting in a poor yield of the N-alkylation product. In contrast, the PdZn/Al2O3 catalyst acted as an efficient catalyst for this reaction, displaying high catalytic activities, selectivities, and atom efficiencies and a wide substrate scope. Detailed kinetic and computational studies revealed that the relative affinity of Pd for alcohol and amine drastically changes by the formation of a PdZn intermetallic phase. On monometallic Pd, the adsorption and activation of amines are preferred over those of alcohols in terms of thermodynamic and kinetic aspects, respectively. However, this trend is inverted on PdZn, allowing preferential adsorption and activation of alcohols and, hence, selective N-alkylation.
- Furukawa, Shinya,Suzuki, Ryohei,Komatsu, Takayuki
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p. 5946 - 5953
(2016/09/09)
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- Iridium(I) Complexes Bearing a Noninnocent PNP-Pincer-Type Phosphaalkene Ligand: Catalytic Application in the Base-Free N-Alkylation of Amines with Alcohols
-
A series of IrI complexes [Ir(L)(PPEP?)] [L = Cl- (3), CO (4), tBuNC (5), PMe3 (6), PPh3 (7)], coordinated with a PNP-pincer-type phosphaalkene ligand bearing a dearomatized pyridine ring (PPEP?), have been prepared and their catalytic properties for the dehydration/condensation of amines with alcohols has been examined. The catalytic reactions successfully proceed under base-free conditions to give N-alkylated amines and their dehydrogenation derivatives (imines). The product selectivity is dependent on L coordinated with Ir(PPEP?). Complexes 4 and 5 that contain π-accepting ligands (CO, tBuNC) form N-alkylated amines as the major products in a closed system using a nitrogen-gas-filled Schlenk tube. In contrast, complex 7 that contain PPh3 as L produces imines as the major products under a nitrogen-gas flow. The reason for the selectivity change depending on L is discussed based on stoichiometric reactions using model compounds of presumed catalytic intermediates. PNP-pincer-type phosphaalkene complexes of IrI bearing a dearomatized pyridine ring have been found to catalyze the dehydration/condensation of amines with alcohols under base-free conditions to afford N-alkylated amines and imines in high yields. The product selectivity can be controlled by the choice of auxiliary ligands (L) as well as the reaction conditions.
- Chang, Yung-Hung,Tanigawa, Ippei,Taguchi, Hiro-Omi,Takeuchi, Katsuhiko,Ozawa, Fumiyuki
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p. 754 - 760
(2016/03/01)
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- Heterogeneous Catalytic Reductive Amination of Carbonyl Compounds with Ni-Al Alloy in Water as Solvent and Hydrogen Source
-
The heterogeneous catalytic reductive amination of carbonyl compounds has been achieved by reactions of ammonium hydroxide and various amines with ketones and aldehydes. The process is based on the application of Raney type Ni-Al alloy in an aqueous medium. The reaction of the carbonyl compounds with the amine provided the corresponding Schiff bases that immediately underwent a reduction to provide primary and secondary amines as products. The controlled reaction of the Al content of the alloy with the solvent water generates hydrogen, and the in situ formed Raney Ni serves as a hydrogenation catalyst. The method is a simple and efficient way of preparing a broad variety of primary and secondary amines.
- Sch?fer, Christian,Ni?anci, Bilal,Bere, Matthew P.,Da?tan, Arif,T?r?k, Béla
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p. 3127 - 3133
(2016/09/09)
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- Nucleophilic substitution reactions of meta- and para-substituted benzylamines with benzyl bromide in methanol medium
-
The rates of reactions of para- and meta-substituted benzylamines with benzyl bromide were measured using conductivity technique in methanol medium. The reaction followed a total second-order path. The end product of the reaction is identified as dibenzylamine (X-C6H4CH2NHCH2C6H5) (where X = 4-OCH3, 4-CH3, H, 4-Cl, 4-CF3, 3-CF3, 4-NO2). Electron-withdrawing groups such as chloro, trifluoromethyl, and nitro in the benzylamine moiety decrease the rate of the reaction, whereas the electron-donating groups, such as methoxy and methyl, increase the rate compared to the unsubstituted compound. A mechanism involving formation of an SN 2-type transition state between the amine nucleophiles and the benzyl bromide and its subsequent decomposition is proposed. Hammett's reaction constant ρ of the reaction decreases with an increase in temperature. Activation parameters were calculated and discussed.
- Ravi,Sanjeev,Jagannadham,Skelton, Adam A.
-
-
- Graphene-supported NiPd alloy nanoparticles: A novel and highly efficient heterogeneous catalyst system for the reductive amination of aldehydes
-
A novel and highly efficient heterogeneous catalytic reductive amination of aldehydes is described. The recently developed graphene supported NiPd alloy nanoparticle (G-NiPd) catalyst using ammonia borane (AB) as a green, stable and safe hydrogen donor was used in a water/methanol mixture (v/v = 2/3) under ambient conditions. The catalytic system was successfully applied in the reductive amination of various substituted aldehydes with amines and the corresponding products were obtained in (up to) 99% yield in 6 h. The G-NiPd catalyst could be recycled up to five times without any significant loss in the product yield.
- Ni?anci, Bilal,Ganjehyan, Khadijeh,Metin, ?nder,Da?tan, Arif,T?r?k, Béla
-
p. 191 - 197
(2015/09/22)
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- Ultrasound-assisted solventless synthesis of amines by in situ oxidation/reductive amination of benzyl halides
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Ultrasound-assisted solventless oxidation/reductive amination of benzyl halides was developed as a facile, efficient, and environmental friendly method toward N-alkylated amines. Aldehydes were formed in situ by oxidation of organic halides with N-methylmorpholine N-oxide (NMO), followed by direct reductive amination with amines using sodium borohydride and montmorillonite K-10 catalyst as the reducing system. This green and simple procedure enables N-alkylated amines to be prepared in good to excellent yields with high selectivity of the monoalkylation. This journal is the Partner Organisations 2014.
- Khumraksa, Bannarak,Phakhodee, Wong,Pattarawarapan, Mookda
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p. 20454 - 20458
(2014/06/09)
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- Pseudorotaxane orientational stereoisomerism driven by π-electron density
-
Pseudo[2]rotaxane orientational isomers were formed in a stereocontrolled way by exploiting the electron-withdrawing (EW) or electron-donating (ED) effects of para-substituted dibenzylammonium axles threaded through the π-electron rich calixarene cavity, which allow the fine tuning of the weak π-π interactions.
- Gaeta, Carmine,Talotta, Carmen,Neri, Placido
-
supporting information
p. 9917 - 9920
(2014/08/18)
-
- Tandem synthesis of amides and secondary amines from esters with primary amines under solvent-free conditions
-
An iridium(III)-catalyzed tandem synthesis of amides and amines from esters under solvent-free conditions is described. A commercially available iridium(III) complex, [Cp*IrCl2]2, with sodium acetate showed the best activity for the synthesis of amides and secondary amines. The amide was formed by ester-amide exchange which generates an alcohol in situ which is subsequently transformed to a secondary amine via hydrogen autotransfer. This synthetic protocol with high atom economy generates water as the sole by-product and can afford amides and amines from various esters in a one-pot reaction, expanding the synthetic versatility of ester transformations.
- Lee, Jeongbin,Muthaiah, Senthilkumar,Hong, Soon Hyeok
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p. 2653 - 2660
(2014/09/17)
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- Reductive amination of aldehydes and amines with an efficient Pd/NiO catalyst
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By applying a simple Pd/NiO catalyst, the reductive amination of amines and aldehydes can progress efficiently under mild reaction conditions, and 24 substituted amines with different structures were synthesized with up to 98% isolated yields.
- Yang, Huimin,Cui, Xinjiang,Deng, Youquan,Shi, Feng
-
supporting information
p. 1314 - 1322
(2014/04/17)
-
- Homogeneous catalytic hydrogenation of amides to amines
-
Hydrogenation of amides in the presence of [Ru(acac)3] (acacH=2,4-pentanedione), triphos [1,1,1-tris- (diphenylphosphinomethyl)ethane] and methanesulfonic acid (MSA) produces secondary and tertiary amines with selectivities as high as 93 % provided that there is at least one aromatic ring on N. The system is also active for the synthesis of primary amines. In an attempt to probe the role of MSA and the mechanism of the reaction, a range of methanesulfonato complexes has been prepared from prepared from [Ru(acac) 3], triphos and MSA, or from reactions of [RuX-(OAc)(triphos)] (X=H or OAc) or [RuH2(CO)(triphos)] with MSA. Crys-tallographically characterised complexes include: [Ru(OAc-κ1O) 2(H2O)-(triphos)], [Ru(OAc-κ2O,O') (CH3SO3-κ1O)(triphos)], [Ru(CH 3SO3-κ1O)2-(H 2O)(triphos)] and [Ru2(μ-CH3SO 3)3-(triphos)2][CH3SO3], whereas other complexes, such as [Ru(OAc-κ1O)(OAc- κ2O,O')(triphos)],[Ru(CH3SO3- κ1O)(CH3SO3-κ2O,O')- (triphos)], H[Ru(CH3SO3-κ1O) 3-(triphos)], [RuH(CH3SO3-κ1O) (CO)-(triphos)] and [RuH(CH3SO3-k2O,O')- (triphos)] have been characterised spectroscopically. The interactions between these various complexes and their relevance to the catalytic reactions are discussed.
- Coetzee, Jacorien,Dodds, Deborah L.,Klankermayer, Jürgen,Brosinski, Sandra,Leitner, Walter,Slawin, Alexandra M. Z.,Cole-Hamilton, David J.
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p. 11039 - 11050
(2013/09/02)
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- Direct reductive amination of aldehydes using lithium-arene(cat.) as reducing system. A simple one-pot procedure for the synthesis of secondary amines
-
A simple one-pot procedure for the direct reductive amination of aldehydes using lithium powder and a catalytic amount of 4,4′-di-tert-butylbiphenyl (DTBB) or a polymer supported naphthalene as reducing system is described. The direct reductive amination of a variety of aldehydes with primary amines was achieved simply by adding a mixture of the corresponding carbonyl compound and the amine, over a solution of the lithium arenide in THF at room temperature. For most of the substrates tested the main reaction products were the secondary amines along with variable amounts of the corresponding alcohol and/or imine products. Theoretical DFT calculations have been applied in order to explain the differences in reactivity observed for aromatic substrates.
- Nador, Fabiana,Moglie, Yanina,Ciolino, Andrés,Pierini, Adriana,Dorn, Viviana,Yus, Miguel,Alonso, Francisco,Radivoy, Gabriel
-
experimental part
p. 3156 - 3160
(2012/08/08)
-
- Ni-Cu/γ-Al2O3 catalyzed N-alkylation of amines with alcohols
-
A γ-Al2O3 supported Ni and Cu bimetallic nanoparticles catalyst (45 wt.% Ni, Ni/Cu mass ratio = 4.5/1.0) is prepared by electroless plating method for the N-alkylation of amines with alcohols under base and Lewis acidic cocatalyst conditions. The catalyst afforded fast conversions, high selectivity for amines and alcohols with various structures under an Ar atmosphere in o-xylene. Furthermore, catalyst still has a stable catalytic activity after two consecutive cycles regenerated.
- Sun, Jian,Jin, Xiaodong,Zhang, Fengwei,Hu, Wuquan,Liu, Juntao,Li, Rong
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experimental part
p. 30 - 33
(2012/07/17)
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- Selective synthesis of secondary amines by Pt nanowire catalyzed reductive amination of aldehydes and ketones with ammonia
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The process of the reductive amination of aldehydes or ketones in the presence of ammonia using unsupported ultra-thin Pt nanowires has been developed. This catalytic system shows high activity and selectivity under mild reaction conditions.
- Qi, Fenqiang,Hu, Lei,Lu, Shuanglong,Cao, Xueqin,Gu, Hongwei
-
supporting information
p. 9631 - 9633
(2012/10/29)
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- Zinc-catalyzed chemoselective reduction of tertiary and secondary amides to amines
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General and convenient procedures for the catalytic hydrosilylation of secondary and tertiary amides under mild conditions have been developed. In the presence of inexpensive zinc catalysts, tertiary amides are easily reduced by applying monosilanes. Key to success for the reduction of the secondary amides is the use of zinc triflate and disilanes with dual Si-H moieties. The presented hydrosilylations proceed with excellent chemoselectivity in the presence of sensitive ester, nitro, azo, nitrile, olefins, and other functional groups, thus making the method attractive for organic synthesis.
- Das, Shoubhik,Addis, Daniele,Junge, Kathrin,Beller, Matthias
-
experimental part
p. 12186 - 12192
(2011/11/07)
-
- A simple flowcell for reactionmonitoring by NMR
-
A simple, cheap and flexible flowcell based on a standard 5mmNMR tube, designed for the monitoring of reactions but of wide applicability, is described. No modification of the NMR instrument is needed, allowing the system to be employed with any conventional NMR probe and magnet. The system is robust and economical in use of reagents, and can be used for studying both homogeneous and heterogeneous reactions.
- Khajeh,Bernstein,Morris
-
scheme or table
p. 515 - 522
(2011/09/14)
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- Selective synthesis of secondary amines via N-alkylation of primary amines and ammonia with alcohols by supported copper hydroxide catalysts
-
The N-alkylation of primary amines and ammonia (in situ generated from urea or aqueous ammonia) with alcohols to secondary amines was efficiently promoted by supported copper hydroxide catalysts, Cu(OH)xAl2O 3 and Cu(OH)x/TiO2. The observed catalysis was truly heterogeneous, and the catalysts could be reused without an appreciable loss of catalytic performance.
- He, Jinling,Yamaguchi, Kazuya,Mizuno, Noritaka
-
supporting information; experimental part
p. 1182 - 1183
(2011/02/28)
-
- Secondary amine formation from reductive amination of carbonyl compounds promoted by lewis acid using the InCl3ZEt3SiH system
-
A robust and reliable method has been developed for reductive amination of primary amines with various aldehydes and ketones using Zn(ClO4) 2.6H20 as a catalyst. [In-H] generated in situ via a combination of InCl3 and Et3SiH is employed as an effective reducing system. A variety of secondary amines can be synthesized in a one-pot procedure in excellent yields.
- Lee, On-Yi,Law, Ka-Lun,Yang, Dan
-
supporting information; experimental part
p. 3302 - 3305
(2009/11/30)
-
- Hydrogen-transfer reductive amination of aldehydes catalysed by nickel nanoparticles
-
Nickel nanoparticles have been found to catalyse the reductive amination of aldehydes by transfer hydrogenation with isopropanol at 76°C. Georg Thieme Verlag Stuttgart.
- Alonso, Francisco,Riente, Paola,Yus, Miguel
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experimental part
p. 1289 - 1292
(2009/04/06)
-
- Reduction and reductive coupling of imines by Sm(II)-based reagents
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The reductive coupling of aldimines and ketimines by a series of Sm(II)-based reagents (SmI2, SmI2-HMPA, SmBr2, Sm{N[Si(CH3)3]2}2, and SmI 2/triethylamine/water) were examined. In general, aldimines and ketimines were efficiently reduced or coupled using reductants that are more powerful than SmI2, and the use of Sm{N[Si(CH3) 3]2}2 led to higher diastereoselectivities in reductive coupling reactions. Surprisingly, only the combination of SmI 2/triethylamine/water was capable of reducing and coupling para-substituted benzaldimines and coupling ketimines.
- Kim, Myeongseob,Knettle, Brian W.,Dahlén, Anders,Hilmersson, G?ran,Flowers II, Robert A.
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p. 10397 - 10402
(2007/10/03)
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- Oxidative N-debenzylation of N-benzyl-N-substituted benzylamines catalyzed by horseradish peroxidase
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A report on the oxidative N-debenzylation of N-benyl-N-substituted benzylamines catalyzed by horseradish peroxidase was presented. A solution of benzylamine in benzene was added to a benzene solution of p-anisaldehyde in 100 ml flask over 10 minutes. Expulsion of proton and hydroxylation yielding α-hydroxylamines were followed by the formation of benzaldehydes and benzylamines.
- Kim, Sung Soo,Jung, Hwan
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p. 555 - 558
(2007/10/03)
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- The reaction of amines with benzyl halides under CO2 atmosphere
-
To find a useful, practical, and ecologically safer way to synthesize protected amines, the reactions of amines with benzyl halides under CO2 atmosphere were systematically examined. For primary amines, the CO2-inserted products were obtained in higher yields in the presence of DBU as a base, under a high pressure of CO2, and in a low-polarity solvent (toluene/hexane 1:1). Secondary amines gave only low yields of CO2-inserted products.
- Shi,Shen
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p. 3357 - 3365
(2007/10/03)
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- EFFECTS OF SUBSTITUENTS IN THE BENZYL BROMIDE ON THE KINETICS OF THE BENZYLATION OF AMINES
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The kinetics of the reactions of 3- and 4-substituted benzyl bromides with amines having various structures in nitrobenzene at 40 deg C were investigated.The 4-substituted benzyl bromides have higher reactivity compared with that calculated on the basis of the linear correlations according to the Hammett-Taft equation for unsubstituted and 3-substituted benzyl bromides containing electron-withdrawning substituents.The reactivity of benzyl bromides containing electron-donating substituents obeys a linear correlation with the ?+ constants.The effects of structural changes in the substrate and the nucleophile on the character of the transition states of the investigated reactions is discussed.
- Shpan'ko, I. V.,Korostylev, A. P.,Rusu, L. N.
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p. 1715 - 1723
(2007/10/02)
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- CHEMICAL INDUCTION OF POLY-CIS CAROTENOID BIOSYNTHESIS
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Key Word Index - Citrus paradisi; Rutaceae; Marsh white seedless grapefruit; carotenoid biosynthesis; bioregulators; poly-cis carotenoids; carotenoids; prolycopene.A new class of synthetic bioregulators is reported which cause the accumulation of poly-cis carotenoids in the flavedo of Marsh white seedless grapefruit.The compounds tested were all secondary amines: dibenzylamine, substituted dibenzylamines (4-F; 4-Cl; 4-Br; 2-, 3- and 4-Me; 4-NO2; 4-CN; 4-Cl; 4'-Me; 4-Me, 4'-NO2), N-benzyl phenethylamine and N-benzyl 2-naphthalenemethylamine.The most effective, 4-chlorodibenzylamine, caused the accumulation of 74 μg/g dry wt of poly-cis carotenoids.Prolycopene was the predominant pigment but substantial amounts of proneurosporene, poly-cis-γ-carotenes and other cis carotenes were also present.The mode of action of these new bioregulators is probably gene derepression, the same as that of the lycopene inducers.However, the secondary amines probably derepress a recessive gene governing the biosynthesis of poly-cis carotenoids; whereas, the lycopene inducers derepress the dominant gene that gives rise to the normall all-trans carotenoids.The new compounds did not seem to inhibit the cyclase(s), as the lycopene inducers do.
- Poling, Stephen M.,Hsu, Wan-Jean,Yokoyama, Henry
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p. 1677 - 1680
(2007/10/02)
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