- Switchable Imine and Amine Synthesis Catalyzed by a Well-Defined Cobalt Complex
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Switchable imine and amine synthesis catalyzed by a tripodal ligand-supported well-defined cobalt complex is presented herein. A large variety of primary alcohols and amines were selectively converted to imines or amines in good to excellent yields. It is discovered that the base plays a crucial role on the selectivity. A catalytic amount of base leads to the imine formation, while an excess loading of base results in the amine product. This strategy on product selectivity also strongly depends on the organometallic catalysts in use. We expect that the present study could provide useful insights toward selective organic synthesis and catalyst design.
- Paudel, Keshav,Xu, Shi,Hietsoi, Oleksandr,Pandey, Bedraj,Onuh, Chuka,Ding, Keying
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supporting information
p. 418 - 426
(2021/02/01)
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- Bidentate geometry-constrained iminopyridyl nickel-catalyzed synthesis of amines or imines via borrowing hydrogen or dehydrogenative condensation
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The efficient Ni-catalyzed N-alkylation of various anilines with alcohols via borrowing hydrogen is reported using a bidentate geometry-constrained iminopyridyl nickel complex as the catalyst. Substituted benzylic alcohols and short/long chain aliphatic alcohols could be applied as the alkylation sources to couple with aromatic and heteroaromatic amines to give a diverse set of N-alkylation outcomes in moderate to excellent yields. The nickel catalytic system was also suitable for aliphatic amines, selectively delivering the corresponding imines via an acceptorless dehydrogenative condensation strategy.
- Jiang, Yong,Hu, Miao,Sun, Nan,Hu, Baoxiang,Shen, Zhenlu,Hu, Xinquan,Jin, Liqun
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supporting information
(2020/11/27)
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- Simple reversible fixation of a magnetic catalyst in a continuous flow system: Ultrafast reduction of nitroarenes and subsequent reductive amination using ammonia borane
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Continuous reductive amination of aldehydes with nitroarenes over a Pd-Pt-Fe3O4 catalyst was performed. We used NH3BH3 as not only a hydrogen source for nitro reduction, but also a reductant for imine reduction. Secondary aromatic amines were obtained in the continuous flow reaction in good to excellent yields.
- Byun, Sangmoon,Cho, Ahra,Kang, Dong Yun,Kim, B. Moon,Kim, Ha Joon,Kim, Hong Won,Kim, Seong Min,Lei, Cao,Park, Jin Kyoon
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p. 944 - 949
(2020/03/11)
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- C–N Cross-coupling Reactions of Amines with Aryl Halides Using Amide-Based Pincer Nickel(II) Catalyst
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Abstract: An approach to C–N cross-coupling reactions of aryl halides with amines in the presence of an amide-based pincer nickel(II) catalyst (2) is described. For 3?h reactions at 110?°C with 0.2?mol% catalyst, aryl bromides gave higher turnover numbers (TON) than the corresponding chlorides or iodides. Both primary and secondary amines could be used with the former giving higher TON. However, sterically hindered amines showed lower TON. In elucidating the mechanism of this nickel complex-catalyzed C–N cross coupling reaction it was found that the rate of reaction was unchanged in the presence of radical quenchers and a plausible Ni(I)–Ni(III) pathway is proposed. Graphic Abstract: [Figure not available: see fulltext.]Nickel pincer catalyst proved to be excellent catalyst for the C-N cross-coupling reaction with the high turnover number (TON) for 1° and 2° amines and different nonactivated aryl halides under optimum conditions.
- Albkuri, Yahya M.,RanguMagar, Ambar B.,Brandt, Andrew,Wayland, Hunter A.,Chhetri, Bijay P.,Parnell, Charlette M.,Szwedo, Peter,Parameswaran-Thankam, Anil,Ghosh, Anindya
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p. 1669 - 1678
(2019/12/27)
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- High-Throughput Screening of Reductive Amination Reactions Using Desorption Electrospray Ionization Mass Spectrometry
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This study describes the latest generation of a high-throughput screening system that is capable of screening thousands of organic reactions in a single day. This system combines a liquid handling robot with desorption electrospray ionization (DESI) mass spectrometry (MS) for a rapid reaction mixture preparation, accelerated synthesis, and automated MS analysis. A total of 3840 unique reductive amination reactions were screened to demonstrate the throughputs that are capable with the system. Products, byproducts, and intermediates were all monitored in full-scan mass spectra, generating a complete view of the reaction progress. Tandem mass spectrometry experiments were conducted to verify the identity of the products formed. The amine and electrophile reactivity trends represented in the data match what is expected from theory, indicating that the system accurately models the reaction performance. The DESI results correlated well with those generated using more traditional mass spectrometry techniques like liquid chromatography-mass spectrometry, validating the data generated by the system.
- Cooks, R. Graham,Ferreira, Christina R.,Li, Yangjie,Logsdon, David L.,Paschoal Sobreira, Tiago Jose,Thompson, David H.
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supporting information
p. 1647 - 1657
(2020/10/26)
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- Alcohol Amination Catalyzed by Copper Powder as a Self-Supported Catalyst
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Catalytic alcohol amination is a sustainable reaction for N-alkyl amine synthesis. Homogeneous and supported copper catalysts have long been studied for this reaction and have given some impressive results. In this study, copper powder is found to behave as an active catalyst for alcohol amination, giving better catalytic performance than metal-oxide-supported nanocopper catalysts. Catalyst characterization suggests that the copper powder can be considered as a self-supported nanocopper catalyst (i.e., nanocopper supported on copper particles). These results might promote the study of unsupported transition metal powders in sustainable catalytic reactions.
- Wu, Yajuan,Huang, Yongji,Dai, Xingchao,Shi, Feng
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p. 3185 - 3191
(2018/11/30)
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- Continuous nitro-reduction and reductive amination reaction using ammoniaborane and magnetic nanoflakes immobilized through external magnetic force
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The present invention provides: a method of continuous reduction of a nitro compound which comprises continuously contacting a magnetic catalyst with a nitro compound and a reducing agent to reduce the nitro compound and continuously supplying an aldehyde compound thereto to continuously produce a secondary amine compound by conducting a reductive amination reaction; and an apparatus for the same.COPYRIGHT KIPO 2019
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Paragraph 0042-0052; 0151-0155
(2019/07/03)
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- Efficient nickel-catalysed: N -alkylation of amines with alcohols
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The selective N-alkylation of amines with alcohols via the borrowing hydrogen strategy represents a prominent sustainable catalytic method, which produces water as the only by-product and is ideally suited for the catalytic transformation of widely available alcohol reaction partners that can be derived from renewable resources. Intensive research has been devoted to the development of novel catalysts that are mainly based on expensive noble metals. However, the availability of homogeneous or heterogeneous non-precious metal catalysts for this transformation is very limited. Herein we present a highly active and remarkably easy-to-prepare Ni based catalyst system for the selective N-alkylation of amines with alcohols, that is in situ generated from Ni(COD)2 and KOH under ligand-free conditions. This novel method is very efficient for the functionalization of aniline and derivatives with a wide range of aromatic and aliphatic alcohols as well as diols and exhibits excellent functional group tolerance including halides, benzodioxane and heteroaromatic groups. Several TEM measurements combined with elemental analysis were conducted in order to gain insight into the nature of the active catalyst and factors influencing reactivity.
- Afanasenko, Anastasiia,Elangovan, Saravanakumar,Stuart, Marc C. A.,Bonura, Giuseppe,Frusteri, Francesco,Barta, Katalin
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p. 5498 - 5505
(2018/11/20)
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- Cobalt-Rhodium Heterobimetallic Nanoparticle-Catalyzed N-Alkylation of Amines with Alcohols to Secondary and Tertiary Amines
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Without the requirement for base or other additives, Co2Rh2/C can selectively catalyze both mono- and bis-N-alkylation through the coupling of simple alcohols with amines, yielding a range of secondary and tertiary amines in good to excellent isolated yields. The reaction can be applied to benzyl alcohol with optically active 1-phenylethan-1-amines, and secondary amines were isolated in quantitative yields with an excellent enantiomeric excess (ee > 94%). Selectivity is achieved by varying the reaction temperature and amount of catalyst used. This catalytic system has several advantages including eco-friendliness and a simple workup procedure. The catalyst can be successfully recovered and reused ten times without any significant loss of activity.
- Chung, Hyunho,Chung, Young Keun
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p. 8533 - 8542
(2018/07/30)
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- An Efficient and Selective Nickel-Catalyzed Direct N-Alkylation of Anilines with Alcohols
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Herein, we developed an efficient and selective nickel-catalyzed monoalkylation of various primary alcohols with aryl and heteroaryl amines together with diols and amino alcohol derivatives. Notably, the catalytic protocol consisting of an earth-abundant and non-precious NiBr2/L1 system enables the transformations in the presence of hydroxyl, alkene, nitrile, and nitro functionalities. As a highlight, we have demonstrated the alkylation of diamine, intramolecular cyclization to N-heterocycles, and functionalization of complex vitamin E, an (±)-α-tocopherol derivative. Preliminary mechanistic studies revealed the participation of a benzylic C-H bond in the rate-determining step.
- Vellakkaran, Mari,Singh, Khushboo,Banerjee, Debasis
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p. 8152 - 8158
(2017/12/08)
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- A Simple Cobalt(II) Chloride Catalyzed N -Alkylation of Amines with Alcohols
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A facile cobalt-catalyzed N -alkylation of amines with alcohols using inexpensive, commercially available CoCl 2 ·6H 2 O is reported. Employing this readily available cobalt catalyst, a variety of amines with wide functional group tolerance were selectively alkylated under benign conditions.
- Midya, Siba P.,Mondal, Akash,Begum, Ayesha,Balaraman, Ekambaram
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supporting information
p. 3957 - 3961
(2017/08/29)
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- Synthesis of 1,3-Amino Alcohols, 1,3-Diols, Amines, and Carboxylic Acids from Terminal Alkynes
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The half-sandwich ruthenium complexes 1-3 activate terminal alkynes toward anti-Markovnikov hydration and reductive hydration under mild conditions. These reactions are believed to proceed via addition of water to metal vinylidene intermediates (4). The functionalization of propargylic alcohols by metal vinylidene pathways is challenging owing to decomposition of the starting material and catalytic intermediates. Here we show that catalyst 2 can be employed to convert propargylic alcohols to 1,3-diols in high yield and with retention of stereochemistry at the propargylic position. The method is also amenable to propargylic amine derivatives, thereby establishing a route to enantioenriched 1,3-amino alcohol products. We also report the development of formal anti-Markovnikov reductive amination and oxidative hydration reactions to access linear amines and carboxylic acids, respectively, from terminal alkynes. This chemistry expands the scope of products that can be prepared from terminal alkynes by practical and high-yielding metal-catalyzed methods.
- Zeng, Mingshuo,Herzon, Seth B.
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p. 8604 - 8618
(2015/09/15)
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- N-alkylation of ammonia and amines with alcohols catalyzed by Ni-loaded CaSiO3
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Nickel nanoparticles loaded onto calcium silicate (Ni/CaSiO3) have been prepared by ion-exchange method followed by in situ H 2-reduction of the calcined precursor. Ni/CaSiO3 was found to be effective for the catalytic direct synthesis of primary amines from alcohols and NH3 under relatively mild conditions. Various aliphatic alcohols are tolerated, and the turnover number (TON) was higher than those of Ru-based homogeneous catalysts. The catalyst was recoverable and was reused. Effects of the surface oxidation states and particle size of Ni on the catalytic activity were studied by infrared (IR) investigation of the states of adsorbed CO and transmission electron microscopy (TEM). It is clarified that the surface Ni0 sites on small (3 nm) sized Ni nanoparticles are the catalytically active species. Ni/CaSiO3 was also effective for the alkylation of anilines and aliphatic amines with various alcohols (benzyl and aliphatic alcohols) under additive free conditions; primary amines were converted into secondary amines and secondary amines into tertiary amines.
- Shimizu, Ken-Ichi,Kanno, Shota,Kon, Kenichi,Hakim Siddiki,Tanaka, Hideyuki,Sakata, Yoshihisa
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p. 134 - 138
(2014/06/09)
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- Heterogeneous Ni catalysts for N-alkylation of amines with alcohols
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Nickel nanoparticles loaded onto various supports (Ni/MOx) have been prepared and studied for the N-alkylation of amines with alcohols. Among the catalysts, Ni/θ-Al2O3 prepared by in situ H 2-reduction of NiO/θ-Al2O3 shows the highest activity, and it acts as reusable heterogeneous catalyst for the alkylation of anilines and aliphatic amines with various alcohols (benzyl and aliphatic alcohols) under additive free conditions. Primary amines are converted into secondary amines and secondary amines into tertiary amines. For the reaction of aniline with an aliphatic alcohol the catalyst shows higher turnover number (TON) than precious metal-based state-of-the-art catalysts. Mechanistic studies suggest that the reaction proceeds through a hydrogen-borrowing mechanism. The activity of Ni catalysts depends on the nature of support materials; acid-base bifunctional supports give higher activity than basic or acidic supports, indicating that acid-base sites on supports are necessary. The presence of basic (pyridine) or acidic (acetic acid) additive in the solution decreased the activity of Ni/θ-Al2O3, which suggests the cooperation of the acid-base site of θ-Al2O3. For a series of Ni/θ-Al2O3 catalysts with different particle size, the turnover frequency (TOF) per surface Ni increases with decreasing Ni mean particle size, indicating that low-coordinated Ni species and/or metal-support interface are active sites. From these results, we propose that the active site for this reaction is metal-support interface, where low-coordinated Ni0 atoms are adjacent to the acid-base sites of alumina.
- Shimizu, Ken-Ichi,Imaiida, Naomichi,Kon, Kenichi,Hakim Siddiki,Satsuma, Atsushi
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p. 998 - 1005
(2013/06/27)
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- Synchronizing steric and electronic effects in {RuII(NNNN,P)} complexes: The catalytic dehydrative alkylation of anilines by using alcohols as a case study
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A series of new hexacoordinated {RuII(NNNN,P)} complexes was prepared from [RuCl2(R3P)3]. Their structure was determined by X-ray crystallography. The catalytic potential of this new class of complexes was tested in the alkylation of aniline with benzyl alcohol. In this test reaction, the influence of the counteranion plus electronic influences at the tetradentate ligand and the phosphine ligand were examined. The electrochemistry of all complexes was studied by cyclic voltammetry. Depending on the substituent at the ligand backbone, the complexes showed a different behavior. For all N-benzyl substituted complexes, reversible Ru II/III redox potentials were observed, whereas the N-methyl substituted complex possessed an irreversible oxidation event at small scan rates. Furthermore, the electronic influence of different substituents at the ligand scaffold and at the phosphine on the RuII/III redox potential was investigated. The measured E0 values were correlated to the theoretically determined HOMO energies of the complexes. In addition, these HOMO energies correlated well with the reactivity of the single complexes in the alkylation of aniline with benzyl alcohol. The exact balance of redox potential and reactivity appears to be crucial for synchronizing the multiple hydrogen-transfer events. The optimized catalyst structure was applied in a screening on scope and limitation in the catalytic dehydrative alkylation of anilines by using alcohols.
- Weickmann, Daniel,Frey, Wolfgang,Plietker, Bernd
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supporting information
p. 2741 - 2748
(2013/03/14)
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- Synthesis of three novel anionic gemini surfactants and comparative studies of their assemble behavior in the presence of bovine serum albumin
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Three novel anionic sulfonate gemini surfactants, sodium 4,4′-(10,19-dioxo-9,11,18,20-tetraazaoctacosane-9,20-diyl) dibenzenesulfonate (Surfactant I), sodium 4,4′-(12,21-dioxo-11,13,20,22- tetraazadotriacontane-11,22-diyl) dibenzenesulfonate (Surfactant II), and sodium 4,4′-(14,23-dioxo-13,15,22,24-tetraazahezatriacontane-13,24-diyl) dibenzenesulfonate (Surfactant III), with different lengths of hydrophobic tail have been synthesized, and their assembly behavior in the presence of bovine serum albumin (BSA) has been studied using spectral methods and molecular modeling methods at physiological pH and 298 K. Critical micelle concentrations (CMCs) of the three surfactants have been determined by surface tension measurements. Despite the obvious decrease of CMC with the increase of tail length, fluorescence spectra have shown much closer CAC in the presence of BSA. Surfactant II shows the highest CAC of 3.19 × 10-5 mol L -1 compared with the other two. The polarity of the microenvironment in BSA-surfactant systems has been investigated using pyrene as the probe. In addition, far-UV CD spectra studied the change of the secondary structure content of BSA caused by the three surfactants. The features of the assembly behavior were discussed by three concentration regions. Surfactant II could unfold the protein much more efficiently than the other two surfactants at low concentration, but at high concentration, the change of the secondary structure and the formation of hydrophobic microenvironment show a direct relationship to the length of the hydrophobic tail with the increase of the surfactant concentration.
- Ge, Yu-Shu,Tai, Shu-Xin,Xu, Zi-Qiang,Lai, Lu,Tian, Fang-Fang,Li, Dong-Wei,Jiang, Feng-Lei,Liu, Yi,Gao, Zhi-Nong
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p. 5913 - 5920
(2012/07/27)
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- Palladium catalyzed N-alkylation of amines with alcohols
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An iron oxide immobilized palladium catalyst was prepared for the N-alkylation of amines with alcohols under base and organic ligand free conditions. Applying the optimized reaction conditions, the coupling reactions of amines and alcohols with various structures could be realized with up to 99% isolated yields. The catalysts were studied by XRD, BET, and XPS and the mechanism was studied by DFT calculations.
- Zhang, Yan,Qi, Xiujuan,Cui, Xinjiang,Shi, Feng,Deng, Youquan
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supporting information; experimental part
p. 1334 - 1338
(2011/03/22)
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- Organic ligand-free alkylation of amines, carboxamides, sulfonamides, and ketones by using alcohols catalyzed by heterogeneous Ag/Mo oxides
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Complicated and expensive organic ligands are normally essential in fine chemical synthesis at preparative or industrial levels. The synthesis of fine chemicals by using heterogeneous catalyst systems without additive organic ligand is highly desirable but severely limited due to their poor generality and rigorous reaction conditions. Here, we show the results of carbon-nitrogen or carbon-carbon bond formation catalyzed by an Ag/Mo hybrid material with specific Ag6Mo10O33 crystal structure. 48 nitrogen- or oxygen-containing compounds, that is, amines, carboxamides, sulfonamides, and ketones, were successfully synthesized through a borrowing-hydrogen mechanism. Up to 99% isolated yields were obtained under relatively mild conditions without additive organic ligand. The catalytic process shows promise for the efficient and economic synthesis of amine, carboxamide, sulfonamide, and ketone derivatives because of the simplicity of the system and ease of operation. Copyright
- Cui, Xinjiang,Zhang, Yan,Shi, Feng,Deng, Youquan
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supporting information; experimental part
p. 1021 - 1028
(2011/03/20)
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- Efficient and clean gold-catalyzed one-pot selective n-alkylation of amines with alcohols
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Atom-efficient direct N-alkylation: An environmentally clean one-pot selective N-alkylation of amines with an equimolar amount of alcohols via a hydrogen autotransfer pathway was achieved over a titania-supported gold catalyst system in good to excellent yields without additive (see scheme).
- He, Lin,Lou, Xia-Bing,Ni, Ji,Liu, Yong-Mei,Cao, Yong,He, He-Yong,Fan, Kang-Nian
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supporting information; experimental part
p. 13965 - 13969
(2011/02/23)
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- A highly active catalyst supported molecular sieves-NaHCO3 mixture for the selective and advantageous N-monoalkylation of amines
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Amines are mono-N-alkylated by alkylmesylates in the presence of catalyst supported molecular sieves-NaHCO3 mixture in a regioselective, chemoselective and non-toxic process. Observed chemoselectivity is supported by 'DFT'.
- Das, Asish R.,Medda, Arunima,Singha, Raghunath,Guchhait, Nikhil
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experimental part
p. 841 - 848
(2010/06/01)
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- Hydrogen-transfer reductive amination of aldehydes catalysed by nickel nanoparticles
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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)
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- New active-iron based reducing system for carbonyl compounds and imines. Stereoselective reduction of cyclic ketones
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The reaction of different carbonyl compounds and imines with a mixture of iron(II) chloride tetrahydrate, an excess of lithium powder, and a catalytic amount of 4,4′-di-tert-butylbiphenyl (DTBB, 5 mol%) in THF at room temperature, led to the formation of the corresponding alcohols and amines, respectively. The process was also applied to the transformation of α,β-unsaturated carbonyl compounds into the corresponding saturated alcohols. The new reducing system exhibited good to excellent diastereoselectivity toward the reduction of different monocyclic and polycyclic ketones.
- Moglie, Yanina,Alonso, Francisco,Vitale, Cristian,Yus, Miguel,Radivoy, Gabriel
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p. 2812 - 2819
(2007/10/03)
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- Buchwald-Hartwig aminations of aryl chlorides: A practical protocol based on commercially available Pd(0)-NHC catalysts
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Commercially available, air- and water-stable naphthoquinone imidazolin-2-ylidene-palladium(0) complexes were found to be highly active one-component catalysts for the amination of aryl halides. With these very robust catalysts, the expensive bases Cs2CO3 or NaOt-Bu traditionally used can be replaced by KOH. A convenient reaction protocol has been developed for the coupling of a wide range of aryl chlorides with primary or secondary amines.
- Goo?en,Paetzold,Briel,Rivas-Nass,Karch,Kayser
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p. 275 - 278
(2007/10/03)
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