- Synergism between Ni and W in the Ni-W/C sulfide catalyst in hydrodenitrogenation of pyridine and hydrodesulfurization of thiophene
-
Parallel hydrodenitrogenation (HDN) of pyridine and hydrodesulfurization (HDS) of thiophene was studied over active-carbon-supported Ni, W, and Ni-W sulfide catalysts at 2 MPa and at 280 and 320 °C. Synergism between Ni and W was observed both in HDN and HDS reactions: the activity of the Ni-W catalyst was higher than the sum of the activities of the Ni and W catalysts. However, the synergistic increase in activity was much higher in HDS than in HDN. This led to a characteristic shift in the HDN/HDS selectivity, which was strongly shifted to the HDS side over the Ni-W catalysts as compared with the Ni and W catalysts. HDS was faster than HDN over the Ni-W catalyst, the rate of both reactions being about the same over the Ni catalyst and HDN being faster than HDS over the W catalyst. The selectivity of all the catalysts was shifted to the HDN side with decreasing temperature. The data are a new example for generalisation of the rule that the synergism in activity of bimetallic sulfide Co-Mo, Ni-Mo, and Ni-W catalysts is higher in HDS than in hydrogenation and HDN.
- Gulkova, Daniela,Zdrazil, Miroslav
-
-
Read Online
- Generation of novel family of reductases from PCR based library for the synthesis of chiral alcohols and amines
-
Biocatalysis has shown tremendous potential in the synthesis of drugs and drug intermediates in the last decade. Screening of novel biocatalysts from the natural genome space is the growing trend to replenish the harsh chemical synthetic routes, commonly used in the pharmaceutical and chemical industry. Here, we report a novel ketoreductase (KERD) and a nitrile reductase isolated from the PCR based library generated from the genome of Rhodococcus ruber and Bacillus subtilis, respectively. Both the proteins are hypothetical in nature as there is no putative homology found in the database, although both the enzymes have significant activity towards the synthesis of chiral alcohols and amines. Enzyme activity over a wide range of substrates (aromatic and aliphatic) for both the novel catalysts was observed. From the unique gene sequence to activity over a broad range of substrate and >99% conversion at higher concentrations (100 mM and above) entitles both the hypothetical enzymes as novel. The novel KERD has shown >99% selectivity for the synthesis of (S)-phenylethanol which makes it a potential candidate for industrial catalysis. The novel nitrile reductase has also shown promising activity for the synthesis of (R)-2-phenylethanolamine, which is a difficult moiety to synthesize chemically. In this report, starting from a homology based library, two highly potent whole cell biocatalysts are obtained.
- Sehajpal, Pallvi,Kirar, Seema,Ghosh, Saptarshi,Banerjee, Uttam Chand
-
-
Read Online
- Hydrogenation of Aliphatic Nitriles to Primary Amines over a Bimetallic Catalyst Ni25.38Co18.21/MgO–0.75Al2O3 Under Atmospheric Pressure
-
Abstract: A mixed oxide supported bimetallic catalyst Ni25.38Co18.21/MgO–0.75Al2O3 was readily prepared and found to be efficient in the hydrogenation of valeronitrile (VN) to amylamine (AA) under atmospheric pressure. Under the optimal conditions: H2 to VN molar ratio of 4:1, NH3 to VN molar ratio of 3:1, reaction temperature of 130?°C and residence time of 5?s, the conversion of VN reached 100% with a AA yield of 70.8%, and a diamylamine (DAA) yield of 25.9%. This catalyst was also active in the hydrogenation of other low carbon aliphatic nitriles to their corresponding primary amines. The characterization results revealed that the catalyst had the properties of large surface area, uniform and fine dispersion of metal particles in the form of Ni/Co alloy with synergy effect between the two metals, which endowed the catalyst with good catalytic performances in the hydrogenation reaction of aliphatic nitriles. Graphic Abstract: [Figure not available: see fulltext.]
- Shi, Dongxu,Zhu, He,Han, Yaping,Zhang, Yuecheng,Zhao, Jiquan
-
-
Read Online
- Comparison of the Catalytic Behaviors of Single Cubane MoFe3S4 and Fe4S4 Clusters toward the Multi-electron Reduction of n-C5H11N3
-
The reduction of n-C5H11N3 by Na2S2O3 was investigated in an aqueous Triton X-100 micellar solution containing methylviologen and 2- (1) or 2- (2). 1 catalyzes the r
- Tanaka, Koji,Moriya, Makoto,Tanaka, Toshio
-
-
Read Online
- Ni2P Nanoalloy as an Air-Stable and Versatile Hydrogenation Catalyst in Water: P-Alloying Strategy for Designing Smart Catalysts
-
Non-noble metal-based hydrogenation catalysts have limited practical applications because they exhibit low activity, require harsh reaction conditions, and are unstable in air. To overcome these limitations, herein we propose the alloying of non-noble metal nanoparticles with phosphorus as a promising strategy for developing smart catalysts that exhibit both excellent activity and air stability. We synthesized a novel nickel phosphide nanoalloy (nano-Ni2P) with coordinatively unsaturated Ni active sites. Unlike conventional air-unstable non-noble metal catalysts, nano-Ni2P retained its metallic nature in air, and exhibited a high activity for the hydrogenation of various substrates with polar functional groups, such as aldehydes, ketones, nitriles, and nitroarenes to the desired products in excellent yields in water. Furthermore, the used nano-Ni2P catalyst was easy to handle in air and could be reused without pretreatment, providing a simple and clean catalyst system for general hydrogenation reactions.
- Fujita, Shu,Yamaguchi, Sho,Yamasaki, Jun,Nakajima, Kiyotaka,Yamazoe, Seiji,Mizugaki, Tomoo,Mitsudome, Takato
-
-
Read Online
- Adhesive functionalized ascorbic acid on CoFe2O4: A core-shell nanomagnetic heterostructure for the synthesis of aldoximes and amines
-
This paper reports on the simple synthesis of novel green magnetic nanoparticles (MNPs) with effective catalytic properties and reusability. These heterogeneous nanocatalysts were prepared by the anchoring of Co and V on the surface of CoFe2O4 nanoparticles coated with ascorbic acid (AA) as a green linker. The prepared nanocatalysts have been identified by scanning electron microscopy, transmission electron microscopy, energy-dispersive X-ray spectroscopy, X-ray atomic mapping, thermogravimetric analysis, X-ray powder diffraction, vibrating sample magnetometer analysis, coupled plasma optical emission spectrometry and Fourier transform infrared spectroscopy. The impact of CoFe2O4@AA-M (Co, V) was carefully examined for NH2OH·HCl oximation of aldehyde derivatives first and then for the reduction of diverse nitro compounds with sodium borohydride (NaBH4) to the corresponding amines under green conditions. The catalytic efficiency of magnetic CoFe2O4@AA-M (Co, V) nanocatalysts was investigated in production of different aldoximes and amines with high turnover numbers (TON) and turnover frequencies (TOF) through oximation and reduction reactions respectively. Furthermore, the developed environment-friendly method offers a number of advantages such as high turnover frequency, mild reaction conditions, high activity, simple procedure, low cost and easy isolation of the products from the reaction mixture by an external magnetic field and the catalyst can be reused for several consecutive runs without any remarkable decrease in catalytic efficiency.
- Sorkhabi, Serve,Ghadermazi, Mohammad,Mozafari, Roya
-
-
Read Online
- Asymmetric synthesis of serinol-monoesters catalyzed by amine transaminases
-
The asymmetric synthesis of serinol-derivatives was investigated employing different amine transaminases as biocatalysts. Under the optimized conditions conversions up to 92% and excellent enantiomeric excesses up to 99% ee were obtained providing access
- Costa, Ingrid C.R.,de Souza, Rodrigo Octavio M.A.,Bornscheuer, Uwe T.
-
-
Read Online
- The influence of carbon laydown on selectivity in the hydrogenation of pentenenitriles over supported-nickel catalysts
-
Pentenenitriles contain two-reducible functionalities: a carbon-carbon double bond and a nitrile group, either of which may undergo hydrogenation during reaction. In this work we show how the deposition of hydrocarbonaceous material on the catalyst surface during pentenenitrile hydrogenation over 16 wt.% Ni/Al2O3 and 10 wt.% Ni/SiO2 catalysts has a significant impact on the observed catalytic activity and selectivity. The role of carbon laydown in controlling catalytic performance in this system has been evaluated through activity measurements and mechanistic studies employing a Tapered Element Oscillating Microbalance (TEOM) and a conventional flow-through reactor. TEOM data indicating the deposition of carbonaceous material during reaction are correlated with kinetic analysis which provides a description of catalyst deactivation in terms of the deactivation of groups of active sites. Specifically five distinct active sites are shown to exist on Ni/Al 2O3 including a hydrogenation site on the support, which is not present in the case of Ni/SiO2. The nature and strength of these sites are discussed. Furthermore, deuteration studies provide mechanistic insights suggesting that the hydrogenation reaction proceeds via a cyclic intermediate. The reported data identify a correlation between mass laydown on specific active sites and deactivation, thereby demonstrating the influence of hydrocarbonaceous deposits on selectivity. Both the location and the nature of such deposits are crucial in determining its influence on reaction.
- McGregor, James,Canning, Arran S.,Mitchell, Scott,Jackson, S. David,Gladden, Lynn F.
-
-
Read Online
- Synthesis of Chiral Amines via a Bi-Enzymatic Cascade Using an Ene-Reductase and Amine Dehydrogenase
-
Access to chiral amines with more than one stereocentre remains challenging, although an increasing number of methods are emerging. Here we developed a proof-of-concept bi-enzymatic cascade, consisting of an ene reductase and amine dehydrogenase (AmDH), to afford chiral diastereomerically enriched amines in one pot. The asymmetric reduction of unsaturated ketones and aldehydes by ene reductases from the Old Yellow Enzyme family (OYE) was adapted to reaction conditions for the reductive amination by amine dehydrogenases. By studying the substrate profiles of both reported biocatalysts, thirteen unsaturated carbonyl substrates were assayed against the best duo OYE/AmDH. Low (5 %) to high (97 %) conversion rates were obtained with enantiomeric and diastereomeric excess of up to 99 %. We expect our established bi-enzymatic cascade to allow access to chiral amines with both high enantiomeric and diastereomeric excess from varying alkene substrates depending on the combination of enzymes.
- Fossey-Jouenne, Aurélie,Jongkind, Ewald P. J.,Mayol, Ombeline,Paul, Caroline E.,Vergne-Vaxelaire, Carine,Zaparucha, Anne
-
-
- Highly selective synthesis of primary amines from amide over Ru-Nb2O5 catalysts
-
Amines are an important class of compounds in natural products and medicines. The universal availability of amides provides a potential way for the synthesis of amines. Herein, Ru/Nb2O5 catalyst is demonstrated to be highly efficient and stable for the selective hydrogenation of propionamide to propylamine (as a model reaction), with up to 91.4% yield of propylamine under relatively mild conditions. Results from XPS analyses, CO chemisorption, TEM images and DRIFTS spectra revealed that the unique properties of Nb2O5 can effectively activate the C=O group of amides, and the smaller Ru particles on Nb2O5 could further promote the activation, leading to superior catalytic performance of Ru/Nb2O5 for amide hydrogenation. Meanwhile, reducing the surface acidity of Nb2O5 can greatly inhibit the side reactions to by-products, and further enhance the selectivity to amine. Moreover, this catalytic system is also applicable for the hydrogenation of a variety of amides and provides high potential for the industrial production of primary amines from amides.
- Guo, Wanjun,Guo, Yong,Jia, Hongyan,Liu, Xiaohui,Pan, Hu,Wang, Yangang,Wang, Yanqin,Xia, Qineng
-
-
- One-pot reductive amination of carboxylic acids: a sustainable method for primary amine synthesis
-
The reductive amination of carboxylic acids is a very green, efficient and sustainable method for the production of (bio-based) amines. However, with current technology, this reaction requires two to three reaction steps. Here, we report the first (heterogeneous) catalytic system for the one-pot reductive amination of carboxylic acids to amines, with solely H2 and NH3 as the reactants. This reaction can be performed with relatively cheap ruthenium-tungsten bimetallic catalysts in the green and benign solvent cyclopentyl methyl ether (CPME). Selectivities of up to 99% for the primary amine could be achieved at high conversions. Additionally, the catalyst is recyclable and tolerant for common impurities such as water and cations (e.g. sodium carboxylate).
- Coeck, Robin,De Vos, Dirk E.
-
supporting information
p. 5105 - 5114
(2020/08/25)
-
- Synthesis of oxalamides by acceptorless dehydrogenative coupling of ethylene glycol and amines and the reverse hydrogenation catalyzed by ruthenium
-
A sustainable, new synthesis of oxalamides, by acceptorless dehydrogenative coupling of ethylene glycol with amines, generating H2, homogeneously catalyzed by a ruthenium pincer complex, is presented. The reverse hydrogenation reaction is also accomplished using the same catalyst. A plausible reaction mechanism is proposed based on stoichiometric reactions, NMR studies, X-ray crystallography as well as observation of plausible intermediates.
- Ben-David, Yehoshoa,Diskin-Posner, Yael,Milstein, David,Zhou, Quan-Quan,Zou, You-Quan
-
p. 7188 - 7193
(2020/07/23)
-
- Cerium-Catalyzed C-H Functionalizations of Alkanes Utilizing Alcohols as Hydrogen Atom Transfer Agents
-
Modern photoredox catalysis has traditionally relied upon metal-to-ligand charge-transfer (MLCT) excitation of metal polypyridyl complexes for the utilization of light energy for the activation of organic substrates. Here, we demonstrate the catalytic application of ligand-to-metal charge-transfer (LMCT) excitation of cerium alkoxide complexes for the facile activation of alkanes utilizing abundant and inexpensive cerium trichloride as the catalyst. As demonstrated by cerium-catalyzed C-H amination and the alkylation of hydrocarbons, this reaction manifold has enabled the facile use of abundant alcohols as practical and selective hydrogen atom transfer (HAT) agents via the direct access of energetically challenging alkoxy radicals. Furthermore, the LMCT excitation event has been investigated through a series of spectroscopic experiments, revealing a rapid bond homolysis process and an effective production of alkoxy radicals, collectively ruling out the LMCT/homolysis event as the rate-determining step of this C-H functionalization.
- An, Qing,Chen, Yuegang,Liu, Weimin,Pan, Hui,Wang, Xin,Wang, Ziyu,Zhang, Kaining,Zuo, Zhiwei
-
supporting information
p. 6216 - 6226
(2020/04/27)
-
- Ambient-Temperature Synthesis of Primary Amines via Reductive Amination of Carbonyl Compounds
-
Efficient synthesis of primary amines via low-temperature reductive amination of carbonyl compounds using NH3 and H2 as the nitrogen and hydrogen resources is highly desired and challenging in the chemistry community. Herein, we employed naturally occurring phytic acid as a renewable precursor to fabricate titanium phosphate (TiP)-supported Ru nanocatalysts with different reduction degrees of RuO2 (Ru/TiP-x, x represents the reduction temperature) by combining ball milling and molten-salt processes. Very interestingly, the obtained Ru/TiP-100 had good catalytic performance for the reductive amination of carbonyl compounds at ambient temperature, resulting from the synergistic cooperation of the support (TiP) and the Ru/RuO2 with a suitable proportion of Ru0 (52%). Various carbonyl compounds could be efficiently converted into the corresponding primary amines with high yields. More importantly, the conversion of other substrates with reducible groups could also be achieved at ambient temperature. Detailed investigations indicated that the partially reduced Ru and the support (TiP) were indispensable. The high activity and selectivity of Ru/TiP-100 catalyst originates from the relatively high acidity and the suitable electron density of metallic Ru0.
- Xie, Chao,Song, Jinliang,Hua, Manli,Hu, Yue,Huang, Xin,Wu, Haoran,Yang, Guanying,Han, Buxing
-
p. 7763 - 7772
(2020/08/21)
-
- Nitrogen-Doped Carbon-Supported Nickel Nanoparticles: A Robust Catalyst to Bridge the Hydrogenation of Nitriles and the Reductive Amination of Carbonyl Compounds for the Synthesis of Primary Amines
-
An efficient method was developed for the synthesis of primary amines either from the hydrogenation of nitriles or reductive amination of carbonyl compounds. The reactions were catalyzed by nitrogen-doped mesoporous carbon (MC)-supported nickel nanoparticles (abbreviated as MC/Ni). The MC/Ni catalyst demonstrated high catalytic activity for the hydrogenation of nitriles into primary amines in high yields (81.9–99 %) under mild reaction conditions (80 °C and 2.5 bar H2). The MC/Ni catalyst also promoted the reductive amination of carbonyl compounds for the synthesis of primary amines at 80 °C and 1 bar H2. The hydrogenation of nitriles and the reductive amination proceeded through the same intermediates for the generation of the primary amines. To the best of our knowledge, no other heterogeneous non-noble metal catalysts have been reported for the synthesis of primary amines under mild conditions, both from the hydrogenation of nitriles and reductive amination.
- Zhang, Yangmin,Yang, Hanmin,Chi, Quan,Zhang, Zehui
-
p. 1246 - 1255
(2019/03/07)
-
- Platinum-(phosphinito-phosphinous acid) complexes as bi-talented catalysts for oxidative fragmentation of piperidinols: An entry to primary amines
-
Platinum-(phosphinito-phosphinous acid) complex catalyzes the oxidative fragmentation of hindered piperidinols according to a hydrogen transfer induced methodology. This catalyst acts successively as both a hydrogen carrier and soft Lewis acid in a one pot-two steps process. This method can be applied to the synthesis of a wide variety of primary amines in a pure form by a simple acid-base extraction without further purification.
- Membrat, Romain,Vasseur, Alexandre,Moraleda, Delphine,Michaud-Chevallier, Sabine,Martinez, Alexandre,Giordano, Laurent,Nuel, Didier
-
p. 37825 - 37829
(2019/12/03)
-
- Organocatalytic Decarboxylation of Amino Acids as a Route to Bio-based Amines and Amides
-
Amino acids obtained by fermentation or recovered from protein waste hydrolysates represent an excellent renewable resource for the production of bio-based chemicals. In an attempt to recycle both carbon and nitrogen, we report here on a chemocatalytic, metal-free approach for decarboxylation of amino acids, thereby providing a direct access to primary amines. In the presence of a carbonyl compound the amino acid is temporarily trapped into a Schiff base, from which the elimination of CO2 may proceed more easily. After evaluating different types of aldehydes and ketones on their activity at low catalyst loadings (≤5 mol%), isophorone was identified as powerful organocatalyst under mild conditions. After optimisation many amino acids with a neutral side chain were converted in 28–99 % yield in 2-propanol at 150 °C. When the reaction is performed in DMF, the amine is susceptible to N-formylation. This consecutive reaction is catalysed by the acidity of the amino acid reactant itself. In this way, many amino acids were efficiently transformed to the corresponding formamides in a one-pot catalytic system.
- Claes, Laurens,Janssen, Michiel,De Vos, Dirk E.
-
p. 4297 - 4306
(2019/08/26)
-
- Selective Synthesis of Primary Amines from Nitriles under Hydrogenation Conditions
-
The hydrogenation of aliphatic nitriles over Pd/C, Pd/Al2O3, and Pd?Au/Al2O3 catalysts were evaluated for the selective hydrogenation of aliphatic nitriles to the corresponding primary amines. The highest selectivity (>99%) toward primary amines was achieved when the reaction was carried out in acetic acid using 10 mol% of 25% Pd-5% Au/Al2O3 under relatively low hydrogen pressure (0.8 MPa). Characterization of the catalysts by XRD, CO adsorption experiments, and EXAFS revealed that the excellent selectivity of 25% Pd-5% Au/Al2O3 toward the synthesis of primary amines is determined by the electronic properties and/or the surface structure resulting from alloying Pd with Au. (Figure presented.).
- Yoshimura, Masatoshi,Komatsu, Akira,Niimura, Masaru,Takagi, Yukio,Takahashi, Tohru,Ueda, Shun,Ichikawa, Tomohiro,Kobayashi, Yutaka,Okami, Hiroki,Hattori, Tomohiro,Sawama, Yoshinari,Monguchi, Yasunari,Sajiki, Hironao
-
p. 1726 - 1732
(2018/03/21)
-
- Cobalt complex, preparation method thereof, and application thereof in selective catalysis of transfer hydrogenation reaction of cyano group
-
The invention discloses a cobalt complex, a preparation method thereof, and an application thereof in the selective catalysis of a transfer hydrogenation reaction of a cyano group. The structural formula of the cobalt complex is represented by formula I. The cobalt complex is prepared through a reaction of a cobalt salt and an NNP ligand or a PNP ligand under the protection of an inert atmosphere;and the chemical formula of the cobalt salt is CoX12, wherein X1 represents halogen, a sulfate radical, a perchlorate radical, a hexafluorophosphate radical, a hexafluoroantimonate radical, a tetrafluoroborate radical, a trifluoromethanesulfonate radical or a tetra(pentafluorophenyl)borate radical. The cobalt complex can be used in the selective catalysis of the transfer hydrogenation reaction ofthe cyano group to obtain a primary amine compound, a secondary amine compound and a tertiary amine compound, the primary amine compound, the secondary amine compound and the tertiary amine compoundare important intermediates in a series of subsequent functionalizing reactions, and the cobalt complex has a very high catalysis activity, and has great research values and a great application prospect.
- -
-
Paragraph 0157-0159; 0162
(2018/05/07)
-
- Low-Pressure Hydrogenation of Nitriles to Primary Amines Catalyzed by Ruthenium Pincer Complexes. Scope and mechanism
-
The catalytic hydrogenation of nitriles to primary amines constitutes an environmentally benign and atom-economical methodology in synthetic organic chemistry. However, selective hydrogenation can be challenging, and usually elevated pressure and the use of various additives is required. Herein the hydrogenation of aromatic and aliphatic nitriles to form primary amines catalyzed by ruthenium pincer complexes is described. The reactions are conducted at low H2 pressure, low catalytic loadings and, in case of a variety of benzonitriles, under neutral conditions and without any additives. Mechanistic insight is provided.
- Mukherjee, Arup,Srimani, Dipankar,Ben-David, Yehoshoa,Milstein, David
-
p. 559 - 563
(2017/02/26)
-
- Cobalt-Catalyzed and Lewis Acid-Assisted Nitrile Hydrogenation to Primary Amines: A Combined Effort
-
The selective hydrogenation of nitriles to primary amines using a bench-stable cobalt precatalyst under 4 atm of H2 is reported herein. The catalyst precursor was reduced in situ using NaHBEt3, and the resulting Lewis acid formed, BEt3, was found to be integral to the observed catalysis. Mechanistic insights gleaned from para-hydrogen induced polarization (PHIP) transfer NMR studies revealed that the pairwise hydrogenation of nitriles proceeded through a Co(I/III) redox process.
- Tokmic, Kenan,Jackson, Bailey J.,Salazar, Andrea,Woods, Toby J.,Fout, Alison R.
-
supporting information
p. 13554 - 13561
(2017/10/05)
-
- Bifunctional N-Doped Co@C Catalysts for Base-Free Transfer Hydrogenations of Nitriles: Controllable Selectivity to Primary Amines vs Imines
-
The transfer hydrogenation of nitriles is an important and alternative strategy to produce primary amines or imines, both of which play a crucial role in the synthesis of fine chemicals and pharmaceuticals. Nevertheless, developing highly active bifunctional catalyst system with controllable selectivity for these reactions still remains a huge challenge. In this study, we presented a bifunctional N-doped Co@C catalyst system (Co@NC) for the selective transfer hydrogenation of nitriles into either primary amines or imines. The Co@NC was prepared by the direct pyrolysis of an N-containing Co-MOF under an inert atmosphere, where the N-containing ligands could be transformed into highly graphitic N-doped carbon, endowing the catalysts with high-density special basic sites, while the Co2+ ions were reduced to uniform Co nanoparticles which were dispersed on or embedded in N-doped graphitic structures. Under base-free conditions with isopropyl alcohol as both proton donor and solvent, the optimized Co@NC-900 (obtained at 900 °C) catalyst could convert nitriles into primary amines or imines at will with surprising selectivities (mostly higher than 90%), depending on the solvent volume added to the reaction systems. Furthermore, a possible reaction mechanism was proposed. The N-derived basic sites on Co@NC could play a role similar to that of the base additives, which not only inhibit the formation of polyamine or prevent the products stacked on the surface of catalysts but also effectively promote the transfer hydrogenation of nitriles. The generated corresponding primary imines could controllably attack the primary imine intermediates to form imines by adjusting the concentration of Co@NC. It is clear that this strategy offers a high-performance catalyst system for base-free transfer hydrogenations of nitriles to selectively produce primary amines vs imines.
- Long, Jilan,Shen, Kui,Li, Yingwei
-
p. 275 - 284
(2017/06/07)
-
- In vitro biocatalytic pathway design: Orthogonal network for the quantitative and stereospecific amination of alcohols
-
The direct and efficient conversion of alcohols into amines is a pivotal transformation in chemistry. Here, we present an artificial, oxidation-reduction, biocatalytic network that employs five enzymes (alcohol dehydrogenase, NADP-oxidase, catalase, amine dehydrogenase and formate dehydrogenase) in two concurrent and orthogonal cycles. The NADP-dependent oxidative cycle converts a diverse range of aromatic and aliphatic alcohol substrates to the carbonyl compound intermediates, whereas the NAD-dependent reductive aminating cycle generates the related amine products with >99% enantiomeric excess (R) and up to >99% conversion. The elevated conversions stem from the favorable thermodynamic equilibrium (K′eq = 1.88 × 1042 and 1.48 × 1041 for the amination of primary and secondary alcohols, respectively). This biocatalytic network possesses elevated atom efficiency, since the reaction buffer (ammonium formate) is both the aminating agent and the source of reducing equivalents. Additionally, only dioxygen is needed, whereas water and carbonate are the by-products. For the oxidative step, we have employed three variants of the NADP-dependent alcohol dehydrogenase from Thermoanaerobacter ethanolicus and we have elucidated the origin of the stereoselective properties of these variants with the aid of in silico computational models.
- Knaus, Tanja,Cariati, Luca,Masman, Marcelo F,Mutti, Francesco G.
-
p. 8313 - 8325
(2017/10/19)
-
- Production of Primary Amines by Reductive Amination of Biomass-Derived Aldehydes/Ketones
-
Transformation of biomass into valuable nitrogen-containing compounds is highly desired, yet limited success has been achieved. Here we report an efficient catalyst system, partially reduced Ru/ZrO2, which could catalyze the reductive amination of a variety of biomass-derived aldehydes/ketones in aqueous ammonia. With this approach, a spectrum of renewable primary amines was produced in good to excellent yields. Moreover, we have demonstrated a two-step approach for production of ethanolamine, a large-market nitrogen-containing chemical, from lignocellulose in an overall yield of 10 %. Extensive characterizations showed that Ru/ZrO2-containing multivalence Ru association species worked as a bifunctional catalyst, with RuO2 as acidic promoter to facilitate the activation of carbonyl groups and Ru as active sites for the subsequent imine hydrogenation.
- Liang, Guanfeng,Wang, Aiqin,Li, Lin,Xu, Gang,Yan, Ning,Zhang, Tao
-
supporting information
p. 3050 - 3054
(2017/03/14)
-
- Mild and Selective Cobalt-Catalyzed Chemodivergent Transfer Hydrogenation of Nitriles
-
Herein, we describe a selective cobalt-catalyzed chemodivergent transfer hydrogenation of nitriles to synthesize primary, secondary, and tertiary amines. The solvent effect plays a key role for the selectivity control. The general applicability of this procedure was highlighted by the synthesis of more than 70 amine products bearing various functional groups in high chemoselectivity. Moreover, this mild system achieved >2000 TONs (turnover numbers) for the transfer hydrogenation of nitriles.
- Shao, Zhihui,Fu, Shaomin,Wei, Mufeng,Zhou, Shaolin,Liu, Qiang
-
supporting information
p. 14653 - 14657
(2016/11/23)
-
- Selective hydrogenation of nitriles to primary amines catalyzed by a novel iron complex
-
Hydrogenation of nitriles to primary amines constitutes an atom-efficient and environmentally benign synthetic reaction. Herein we present a novel complex based on earth-abundant iron, and its application in the catalytic homogeneous hydrogenation of (hetero)aromatic, benzylic, and aliphatic nitriles to selectively form primary amines.
- Chakraborty, Subrata,Leitus, Gregory,Milstein, David
-
supporting information
p. 1812 - 1815
(2016/02/05)
-
- Dehydration of 5-amino-1-pentanol over rare earth oxides
-
Vapor-phase catalytic dehydration of 5-amino-1-pentanol was investigated over various oxide catalysts including rare earth oxides (REOs). Over ordinary acidic oxides such as Al2O3, SiO2, SiO2-Al2O3, TiO2, and ZrO2, a cyclic amine such as piperidine was mainly produced at temperatures of 300 °C and higher. In contrast, basic REOs with a cubic bixbyite structure showed the catalytic activity in the conversion of 5-amino-1-pentanol to produce 4-penten-1-amine at 425 °C. In REO catalysts, Tm2O3, Yb2O3, and Lu2O3 showed the high conversion of 5-amino-1-pentanol and the high selectivity to 4-penten-1-amine. Especially, Yb2O3 calcined at 800 °C showed a high formation rate of 4-penten-1-amine with the selectivity of ca. 90% at 425 °C. In comparing the reactivity of several amino alcohols to form the corresponding unsaturated amines, Yb2O3 effectively catalyzed the dehydration of 6-amino-1-hexanol into 5-hexen-1-amine, whereas 3-amino-1-propanol and 4-amino-1-butanol were not effectively dehydrated due to the decomposition of the reactant.
- Ohta, Kaishu,Yamada, Yasuhiro,Sato, Satoshi
-
-
- Selective Hydrogenation of Nitriles to Primary Amines Catalyzed by a Cobalt Pincer Complex
-
The catalytic hydrogenation of nitriles to primary amines represents an atom-efficient and environmentally benign reduction methodology in organic chemistry. This has been accomplished in recent years mainly with precious-metal-based catalysts, with a single exception. Here we report the first homogeneous Co-catalyzed hydrogenation of nitriles to primary amines. Several (hetero)aromatic, benzylic, and aliphatic nitriles undergo hydrogenation to the corresponding primary amines in good to excellent yields under the reaction conditions.
- Mukherjee, Arup,Srimani, Dipankar,Chakraborty, Subrata,Ben-David, Yehoshoa,Milstein, David
-
supporting information
p. 8888 - 8891
(2015/08/03)
-
- Preparation and characterization of primary amines by potassium borohydride-copper chloride system from nitriles
-
Nitriles undergo reduction to primary amines under optimized conditions at 50 °C using 0.25 equiv of copper chloride and 3.0 equiv of potassium borohydride in 80 % isopropanol. The aromatic and aralkyl nitriles could be effectively reduced in yield ranging from 60 to 90 %.
- Jiang, Han,Hu, Jialei,Xu, Xinliang,Zhou, Yifeng
-
p. 3564 - 3566
(2015/12/30)
-
- Transfer hydrogenation of unsaturated bonds in the absence of base additives catalyzed by a cobalt-based heterogeneous catalyst
-
A novel non-noble Co@C-N catalytic system has been developed for catalytic transfer hydrogenation reactions. Co@C-N was found to be highly active and selective in the hydrogenation of a variety of unsaturated bonds with isopropanol in the absence of base additives.
- Long, Jilan,Zhou, Ying,Li, Yingwei
-
supporting information
p. 2331 - 2334
(2015/02/05)
-
- Tungsten and rhenium as hydrogenation agents in the hydrodenitrogenation of pyridine using stacked bed catalyst systems
-
This study analyses the hydrodenitrogenation (HDN) of pyridine using a stacked bed catalyst system, composed of a first hydrogenating bed of Re/γ-Al2O3 or W/γ-Al2O3, over a second bed of Ni-Re/γ-Al2O3 (HDN bed). Using potentiometric methods, it can be seen that the Re/γ-Al2O3 shows higher acidic strength than the W/γ-Al2O3. The results show that higher activity levels are obtained working with stacked bed systems compared to the separate catalysts. These results suggest that the incorporation of the catalyst Re/γ-Al2O3 or W/γ-Al2O3 beds would favour the formation of hydrogenated intermediary products, facilitating the removal of N-containing molecules via HDN on the Ni-Re/γ-Al2O3 catalyst.
- Bassi,Villarroel,Llambías, F.J. Gil,Camú,Baeza
-
p. 2931 - 2934
(2015/11/03)
-
- Amination of ω-Functionalized Aliphatic Primary Alcohols by a Biocatalytic Oxidation-Transamination Cascade
-
Amination of non-activated aliphatic fatty alcohols to the corresponding primary amines was achieved through a five-enzyme cascade reaction by coupling a long-chain alcohol oxidase from Aspergillus fumigatus (LCAO-Af) with a ω-transaminase from Chromobacterium violaceum (ω-TA-Cv). The alcohol was oxidized at the expense of molecular oxygen to yield the corresponding aldehyde, which was subsequently aminated by the PLP-dependent ω-TA to yield the final primary amine product. The overall cascade was optimized with respect to pH, O2 pressure, substrate concentration, decomposition of H2O2 (derived from alcohol oxidation), NADH regeneration, and biocatalyst ratio. The substrate scope of this concept was investigated under optimized conditions by using terminally functionalized C4-C11 fatty primary alcohols bearing halogen, alkyne, amino, hydroxy, thiol, and nitrile groups.
- Pickl, Mathias,Fuchs, Michael,Glueck, Silvia M.,Faber, Kurt
-
p. 3121 - 3124
(2015/10/19)
-
- Conversion of alcohols to enantiopure amines through dual-enzyme hydrogen-borrowing cascades
-
α-Chiral amines are key intermediates for the synthesis of a plethora of chemical compounds at industrial scale. We present a biocatalytic hydrogen-borrowing amination of primary and secondary alcohols that allows for the efficient and environmentally benign production of enantiopure amines. The method relies on a combination of two enzymes: an alcohol dehydrogenase (from Aromatoleum sp., Lactobacillus sp., or Bacillus sp.) operating in tandem with an amine dehydrogenase (engineered from Bacillus sp.) to aminate a structurally diverse range of aromatic and aliphatic alcohols, yielding up to 96% conversion and 99% enantiomeric excess. Primary alcohols were aminated with high conversion (up to 99%). This redox self-sufficient cascade possesses high atom efficiency, sourcing nitrogen from ammonium and generating water as the sole by-product.
- Mutti, Francesco G.,Knaus, Tanja,Scrutton, Nigel S.,Breuer, Michael,Turner, Nicholas J.
-
p. 1525 - 1529
(2015/10/05)
-
- Highly efficient one step synthesis of primary amines from B-Chlorodialkylboranes
-
A convenient and simple method for synthesis of primary amines has been developed by direct amination of B-Chlorodialkylboranes. This general procedure has been applied to synthesize acyclic, cyclic, hindered and chiral amines in very high yields using both hydroxylamine-O-sulfonic acid and monochloroamine as reagents.
- Malhotra, Sanjay V.,Brown, Herbert C.
-
experimental part
p. 383 - 385
(2012/08/28)
-
- Supported p-toluenesulfonic acid as a highly robust and eco-friendly isocyanide scavenger
-
We document here the use of polymer-supported p-toluenesulfonic acid as a highly effective, robust, economical and eco-friendly isocyanide scavenger. The herein described strategy circumvent the intense and repulsive odor of volatile isocyanides, enabling simplified and odorless workup and purifications. The usefulness of the new scavengers has been validated in a set of diverse isocyanide-based organic transformations and this approach is also amenable to parallel synthesis techniques.
- Azuaje, Jhonny,Coelho, Alberto,Maatougui, Abdelaziz El,Blanco, Jose Manuel,Sotelo, Eddy
-
experimental part
p. 89 - 95
(2011/04/15)
-
- Ni//Mo synergism via hydrogen spillover, in pyridine hydrodenitrogenation
-
The pyridine hydrodenitrogenation (HDN) over physically separated stacked Ni//Mo beds was investigated using a continuous-flow high pressure (3 MPa) stainless steel microreactor. Results prove the existence of synergism between physically separated beds of Ni-/γ-Al2O3 and Mo/γ-Al2O3 catalysts for the pyridine hydrodenitrogenation reaction. This synergism is explained by the formation of hydrogen spillover. Product analysis of the pyridine hydrodenitrogenation over Ni//Mo stacked beds suggested that the hydrogen spillover modified the active sites of the MoS2 by increasing the hydrogenation sites.
- Valdevenito,García,Escalona,Gil-Llambias,Rasmussen,López-Agudo
-
experimental part
p. 1154 - 1156
(2010/11/16)
-
- PROCESS FOR PREPARING AMINES FROM ALCOHOLS AND AMMONIA
-
The present invention provides novel ruthenium based catalysts, and a process for preparing amines, by reacting a primary alcohol and ammonia in the presence of such catalysts, to generate the amine and water. According to the process of the invention, primary alcohols react directly with ammonia to produce primary amines and water in high yields and high turnover numbers. This reaction is catalyzed by novel ruthenium complexes, which are preferably composed of quinolinyl or acridinyl based pincer ligands.
- -
-
Page/Page column 26; 32
(2010/04/03)
-
- Triggered self-assembly of simple dynamic covalent surfactants
-
(Figure Presented) A prototype surfactant system was developed with the unique feature that it can be switched between an aggregated, amphiphilic state and a nonaggregated, nonamphiphilic state using external stimuli. This switchable surfactant system uses the reversible formation of a dynamic covalent bond for pH- and temperature-triggered on/off self-assembly of micellar aggregates by reversible displacement of the equilibrium between nonamphiphilic building blocks and their amphiphilic counterparts. The potential for application in controlled-release systems is shown by reversible uptake and release of an organic dye in aqueous media.
- Minkenberg, Christophe B.,Florusse, Louw,Eelkema, Rienk,Koper, Ger J. M.,Van Esch, Jan H.
-
supporting information; scheme or table
p. 11274 - 11275
(2011/03/19)
-
- Selective synthesis of primary amines directly from alcohols and ammonia
-
(Chemical Equation Presented) Air stable and waterproof: Selective and efficient synthesis of primary amines directly from alcohols and ammonia is achieved under mild conditions (see scheme). The reaction is homogenously catalyzed by a novel air-stable ruthenium pincer complex and can proceed in toluene or even in the absence of solvent or "on water".
- Gunanathan, Chidambaram,Milstein, David
-
supporting information; experimental part
p. 8661 - 8664
(2009/05/15)
-
- Supramolecular solid-gas complexes: A thermodynamic approach
-
(Table Presented) Phasing up to complex problems: A thermodynamic approach based on solution data has been proposed for the determination of the stability of gas complexes and elucidation of the selectivity of gas binding. Stability constants, reaction enthalpies, and entropies for the complexation of gaseous guests (n-alkylamines) by solid macrocyclic hosts (β-cyclodextrin, cucurbit[6]uril) were calculated by using the Born-Haber type cycle (see picture).
- Grechin, Alexander G.,Buschmann, Hans-Juergen,Schollmeyer, Eckhard
-
p. 6499 - 6501
(2008/09/17)
-
- Base induced carbon-nitrogen (C=N) double bond migration in Schiff bases
-
Various Schiff bases have been prepared to study base induced carbon-nitrogen double bond migrations. Schiff bases derived from aliphatic aldehydes display highest selectivity. Hydrolysis of the resulting rearranged Schiff base provides an entry to make amines from aldehydes. The reaction has possible practical application.
- Gangadasu,Narender,China Raju,Jayathirtha Rao
-
p. 2598 - 2600
(2007/10/03)
-
- Structure-selectivity relationship in the chemoselective hydrogenation of unsaturated nitriles
-
Several unsaturated nitriles of various structures (cinnamonitrile, cyclohex-1-enyl-acetonitrile, acrylonitrile, 3,3-dimethyl-acrylonitrile, geranylnitrile, and 2- and 3-pentenenitrile) with different substituents at the double bond were hydrogenated over
- Kukula, Pavel,Koprivova, Klara
-
p. 161 - 171
(2007/10/03)
-
- The facile preparation of primary and secondary amines via an improved Fukuyama-Mitsunobu procedure. Application to the synthesis of a lung-targeted gene delivery agent
-
An efficient modification of the Fukuyama-Mitsunobu procedure has been developed whereby primary or secondary amines can be synthesized from alkyl alcohols and the corresponding nosyl-protected/activated amine. Most importantly, the use of the DTBAD and diphenylpyridinylphosphine, as Mitsunobu reagents, generates reaction by-products that can be easily removed, providing a remarkably clean product mixture. This improved technique was implemented in the synthesis of a complex lipopeptide designed to target α 9β1-integrin proteins predominant on upper airway epithelial cells. The Royal Society of Chemistry 2005.
- Guisado, Cristina,Waterhouse, Jodie E.,Price, Wayne S.,Jorgensen, Michael R.,Miller, Andrew D.
-
p. 1049 - 1057
(2007/10/03)
-
- Structure-stability correlations for imine formation in aqueous solution
-
Imine formation between 25 aldehydes and 13 amines in aqueous solution in the pH range 7-11 was studied by 1H NMR spectroscopy. A three-parameter linear equation correlating logarithms of imine formation constants with pKa and HOMO energies of amines and LUMO energies of aldehydes is proposed. In view of the widespread occurrence of imine-forming processes in both chemistry and biology, the data presented are of significance for physical organic chemistry and of particular interest for dynamic combinatorial chemistry. Copyright
- Godoy-Alcantar,Yatsimirsky, Anatoly K.,Lehn
-
p. 979 - 985
(2007/10/03)
-
- Non-metallocene compounds, method for the production thereof and use of the same for the polymerisation of olefins
-
The invention relates to a method for producing special transition metal compounds, to novel transition metal compounds and to the use of the same for the polymerisation of olefins.
- -
-
-
- Synthesis of Primary Amines: First Homogeneously Catalyzed Reductive Amination with Ammonia
-
(Matrix Presented) The synthesis of primary amines via reductive amination of the corresponding carbonyl compounds with aqueous ammonia is achieved for the first time with soluble transition metal complexes. Up to an 86% yield and a 97% selectivity for benzylamines were obtained in the case of various benzaldehydes by using a Rh-catalyst together with water-soluble phosphine and ammonium acetate. In the case of aliphatic aldehydes, a bimetallic catalyst based on Rh/Ir gave improved results.
- Gross, Thoralf,Seayad, Abdul Majeed,Ahmad, Moballigh,Beller, Matthias
-
p. 2055 - 2058
(2007/10/03)
-
- 2-aminopyridine derivatives and combinatorial libraries thereof
-
The present invention relates to novel 2-aminopyridine derivative compounds of the following formula: wherein R1to R5have the meanings provided herein. The invention further relates to combinatorial libraries containing two or more such compounds, as well as methods of preparing 2-aminopyridine derivative compounds.
- -
-
-
- Catalysis of ester aminolysis by cyclodextrins. The reaction of alkylamines with p-nitrophenyl alkanoates
-
The effects of four cyclodextrins (α-CD, β-CD, hydroxypropyl-β-CD, and γ-CD) on the aminolysis of p-nitrophenyl alkanoates (acetate to heptanoate) by primary amines (n-propyl to n-octyl, isobutyl, isopentyl, cyclopentyl, cyclohexyl, benzyl) in aqueous solution have been investigated. Rate constants for amine attack on the free and CD-bound esters (k(N) and k(cN)) have ratios (k(cN)/k(N)) varying from 0.08 (retardation) to 180 (catalysis). For the kinetically equivalent process of free ester reacting with CD-bound amine (k(Nc)), the ratios k(Nc)/k(N) vary from 0.2 to 28. Either way, there is evidence of catalysis in some cases and retardation in others. Changes in reactivity parameters with structure indicate more than one mode of transition state binding to the CDs. Short esters react with short alkylamines by attack of free amine on the ester bound by its aryl group, but for longer amines, free ester reacts with CD-bound amine. Reaction of long esters with long amines, which is catalyzed by β-CD and γ-CD, involves inclusion of the alkylamino group and possibly the ester acyl group. The larger cavity of γ-CD may allow the inclusion of the ester aryl group, as well as the alkylamino group, in the transition state. Reaction between an ester bound to the CD by its acyl group and free amine appears not to be important.
- Gadosy,Boyd,Tee
-
p. 6879 - 6889
(2007/10/03)
-
- The first efficient hydroaminomethylation with ammonia: With dual metal catalysts and two-phase catalysis to primary amines
-
Primary and unbranched secondary amines are obtained by the highly selective hydroaminomethylation of olefins with ammonia [Eq. (a)]. The selectivity is readily controlled with a new dual Rh/Ir catalyst in a two- phase system.
- Zimmermann, Burkhard,Herwig, Juergen,Beller, Matthias
-
p. 2372 - 2375
(2007/10/03)
-
- MCM-silylamine Pd(II)complex: A heterogeneous catalyst for selective azide reductions
-
Palladium complex immobilized on MCM-41 catalyses the reduction of alkyl, aryl and arylsulfonyl azides to the corresponding amines in excellent yields under mild conditions.
- Kantam, M. Lakshmi,Chowdari, N. Srcenivasa,Rahman, Ateeq,Choudary
-
p. 1413 - 1414
(2007/10/03)
-
- Pyridine hydrodenitrogenation catalysed, under atmospheric pressure, by Ni and Mo oxynitrides and MoNi, MoPNi, AlNi and AlPNi mixed oxynitrides
-
Hydrodenitrogenation of pyridine has been realized, under atmospheric pressure, in the presence of oxymtride catalysts of molybdenum, nickel and their solid solutions as well as on mixed catalysts MoNi, MoPNi, AlNi and AlPNi. In all cases, the main reaction products are n-pentane and N- pentylpiperidine, at any conversion. Kinetic results suggest that the conversion of pyridine, on nickel oxynitride, proceeds through successive steps with hydrogenation as rate-limiting. Molybdenum oxynitride and Mo-Ni-N solid solutions tested in the temperature range 500°C-540°C, showed a good structural and catalytic stability, but a low catalytic activity. On the other hand, nickel oxynitride catalyst yielded hitcher activity at much lower temperatures (190°C- 250°C). X-rays analysis indicates that the used catalyst was entirely reduced to metallic nickel, which is the active phase. Under the same experimental conditions, mixed catalysts are relatively less active but more selective than nickel oxynitride into n-pentane formation.
- Elkamel,Elidrissi,Yacoubi,Nadiri,Abouarnadasse
-
p. 2157 - 2179
(2007/10/03)
-