100-46-9

Preparation and characterization of primary amines by potassium borohydride-copper chloride system from nitriles

Jiang, Han,Hu, Jialei,Xu, Xinliang,Zhou, Yifeng

, p. 3564 - 3566 (2015)

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 %.

Electronic Effect of Ruthenium Nanoparticles on Efficient Reductive Amination of Carbonyl Compounds

Komanoya, Tasuku,Kinemura, Takashi,Kita, Yusuke,Kamata, Keigo,Hara, Michikazu

, p. 11493 - 11499 (2017)

Highly selective synthesis of primary amines over heterogeneous catalysts is still a challenge for the chemical industry. Ruthenium nanoparticles supported on Nb2O5 act as a highly selective and reusable heterogeneous catalyst for the low-temperature reductive amination of various carbonyl compounds that contain reduction-sensitive functional groups such as heterocycles and halogens with NH3 and H2 and prevent the formation of secondary amines and undesired hydrogenated byproducts. The selective catalysis of these materials is likely attributable to the weak electron-donating capability of Ru particles on the Nb2O5 surface. The combination of this catalyst and homogeneous Ru systems was used to synthesize 2,5-bis(aminomethyl)furan, a monomer for aramid production, from 5-(hydroxymethyl)furfural without a complex mixture of imine byproducts.

A Mild and Base-Free Protocol for the Ruthenium-Catalyzed Hydrogenation of Aliphatic and Aromatic Nitriles with Tridentate Phosphine Ligands

Adam, Rosa,Bheeter, Charles Beromeo,Jackstell, Ralf,Beller, Matthias

, p. 1329 - 1334 (2016)

A novel protocol for the general hydrogenation of nitriles in the absence of basic additives is described. The system is based on the combination of [Ru(cod)(methylallyl)2] (cod=cyclooctadiene) and L2. A variety of aromatic and aliphatic nitriles is hydrogenated under mild conditions (50 °C and 15 bar H2) with this system. Kinetic studies revealed higher activity in the case of aromatic nitriles compared with aliphatic ones.

Total synthesis of capsaicin analogues from lignin-derived compounds by combined heterogeneous metal, organocatalytic and enzymatic cascades in one pot

Anderson, Mattias,Afewerki, Samson,Berglund, Per,Cordova, Armando

, p. 2113 - 2118 (2014)

The total synthesis of capsaicin analogues was performed in one pot, starting from compounds that can be derived from lignin. Heterogeneous palladium nanoparticles were used to oxidise alcohols to aldehydes, which were further converted to amines by an enzyme cascade system, including an amine transaminase. It was shown that the palladium catalyst and the enzyme cascade system could be successfully combined in the same pot for conversion of alcohols to amines without any purification of intermediates. The intermediate vanillylamine, prepared with the enzyme cascade system, could be further converted to capsaicin analogues without any purification using either fatty acids and a lipase, or Schotten-Baumann conditions, in the same pot. An aldol compound (a simple lignin model) could also be used as starting material for the synthesis of capsaicin analogues. Using L-alanine as organocatalyst, vanillin could be obtained by a retro-aldol reaction. This could be combined with the enzyme cascade system to convert the aldol compound to vanillylamine in a one-step one-pot reaction.

Tandem dehydrogenation of ammonia borane and hydrogenation of nitro/nitrile compounds catalyzed by graphene-supported NiPd alloy nanoparticles

Goeksu, Haydar,Ho, Sally Fae,Metin, Oender,Korkmaz, Katip,Mendoza Garcia, Adriana,Gueltekin, Mehmet Serdar,Sun, Shouheng

, p. 1777 - 1782 (2014)

We report a facile synthesis of monodisperse NiPd alloy nanoparticles (NPs) and their assembly on graphene (G) to catalyze the tandem dehydrogenation of ammonia borane (AB) and hydrogenation of R-NO2 and/or R-CN to R-NH2 in aqueous methanol solutions at room temperature. The 3.4 nm NiPd alloy NPs were prepared by coreduction of nickel(II) acetate and palladium(II) acetlyacetonate by borane-tert-butylamine in oleylamine and deposition on G via a solution phase self-assembly process. G-NiPd showed composition-dependent catalysis on the tandem reaction with G-Ni 30Pd70 being the most active. A variety of R-NO 2 and/or R-CN derivatives were reduced selectively into R-NH 2 via G-Ni30Pd70 catalyzed tandem reaction in 5-30 min reaction time with the conversion yields reaching up to 100%. Our study demonstrates a new approach to G-NiPd-catalyzed dehydrogenation of AB and hydrogenation of R-NO2 and R-CN. The G-NiPd NP catalyst is efficient and reusable, and the reaction can be performed in an environment-friendly process with short reaction times and high yields.

A Pd/CeO2 “H2 Pump” for the Direct Amination of Alcohols

Yan, Zhen,Tomer, Ajay,Perrussel, Gaetan,Ousmane, Mohamad,Katryniok, Benjamin,Dumeignil, Franck,Ponchel, Anne,Liebens, Armin,Pera-Titus, Marc

, p. 3347 - 3352 (2016)

A Pd/CeO2 catalyst with a prominent reversible H2 storage capacity revealed a high activity and selectivity in the direct amination of benzyl alcohol with aniline and ammonia via the borrowing hydrogen mechanism.

Synthesis of new Copper Catalyst with Pyrazole Based Tridentate Ligand and Study of Its Activity for Azide Alkyne Coupling

Rajeswari, Panneer Selvam,Nagarajan, Rajendran,P, Sujith K,Emmanuvel, Lourdusamy

, (2021)

Synthesis of new copper catalyst with pyrazole based tridentate ligand and study of its activity for azide alkyne coupling were investigated by researchers. To a solution of acetyl acetone (2.002 g, 20 mmol), 2- nitrophenylhydrazine in ethanol was added five drops of con. HCl and heated at 50° for 1 hour. After confirming the formation of 3, 5-dimethyl-1-(2-nitrophenyl)- 1H-pyrazole by TLC, ice cooled water was added in to the reaction mixture. The precipitate was filtered, washed with water and then hexane. The product formed as yellow precipitate, that precipitate had been filtered by normal filter paper. The product was recrystallized in ethanol. For synthesis, was suspended in 6 mL of deionized and stirred for 4 h until a clear solution was obtained in 50 ml round bottom flask Cu(OAc) 2. The reaction mixture was diluted with water, filtered, washed sequentially with water, methanol and n-hexane. Then dark greenish blue color crystal were formed and used for the reactions. The solid was crystallized in CH2Cl2 to get crystal whose structure was confirmed by single crystal XRD.

The reduction of aromatic oximes to amines with borohydride exchange resin-nickel acetate system

Bandgar,Nikat,Wadgaonkar

, p. 863 - 869 (1995)

Aromatic oximes were reduced to the corresponding amines with borohydride supported on an ion exchange resin (BER)- nickel acetate in methanol in good yields. The isolation of pure products by simple filtration and evaporation is an important feature of this method.

Reduction of Azides to Amines with Sodium Borohydride in Tetrahydrofuran with Dropwise Addition of Methanol

Soai, Kenso,Yokoyama, Shuji,Ookawa, Atsuhiro

, p. 48 - 49 (1987)

Azidoalkanes, azidoarenes, and tosyl azide are reduced to the corresponding amines or p-toluenesulfonamide, respectively, by reaction with sodium borohydride in tetrahydrofuran with dropwise addition of small amounts of methanol.

Platinum-(phosphinito-phosphinous acid) complexes as bi-talented catalysts for oxidative fragmentation of piperidinols: An entry to primary amines

Membrat, Romain,Vasseur, Alexandre,Moraleda, Delphine,Michaud-Chevallier, Sabine,Martinez, Alexandre,Giordano, Laurent,Nuel, Didier

, p. 37825 - 37829 (2019)

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.

Pyridonate-Supported Titanium(III). Benzylamine as an Easy-To-Use Reductant

Chong, Eugene,Xue, Wei,Storr, Tim,Kennepohl, Pierre,Schafer, Laurel L.

, p. 4941 - 4945 (2015)

The reaction of bis(3-phenyl-2-pyridonate)Ti(NMe2)2 with excess benzylamine leads to an unexpected reduction of the metal center from Ti(IV) to Ti(III). The reduced titanium species was isolated and revealed as tris(3-phenyl-2-pyrido

Mild catalytic deoxygenation of amides promoted by thorium metallocene

Eisen, Moris S.,Saha, Sayantani

, p. 12835 - 12841 (2020)

The organoactinide-catalyzed (Cp*2ThMe2) hydroborated reduction of a wide range of tertiary, secondary, and primary amides to the corresponding amines/amine-borane adductsviadeoxygenation of the amides is reported herein. The catalytic reactions proceed under mild conditions with low catalyst loading and pinacolborane (HBpin) concentration in a selective fashion. Cp*2ThMe2is capable of efficiently catalysing the gram-scale reaction without a drop in efficiency. The amine-borane adducts are successfully converted into free amine products in high conversions, which increases the usefulness of this catalytic system. A plausible mechanism is proposed based on detailed kinetics, stoichiometric, and deuterium labeling studies.

Molecular Addition Compounds. 11. N-Ethyl-N-isopropylaniline-Borane, a Superior Reagent for Hydroborations and Reductions

Brown, Herbert C.,Kanth, J. V. Bhaskar,Zaidlewicz, Marek

, p. 5154 - 5163 (1998)

Hydroboration studies with a new, highly reactive amine-borane adduct, H3B-NPhEtPri, and representative olefins, such as 1-hexene, styrene, β-pinene, cyclopentene, norbornene, cyclohexene, 2-methyl-2-butene, α-pinene, and 2,3-dimethyl-2-butene, in tetrahydrofuran, dioxane, tert-butyl methyl ether, n-pentane, and dichloromethane, at room temperature (22 ± 3°C) were carried out. The reactions are faster in dioxane, requiring 0.5-1 h for the hydroboration of simple, unhindered olefins to the trialkylborane stage. Moderately hindered olefins, such as cyclohexene and 2-methyl-2-butene, give the corresponding dialkylboranes rapidly, with further hydroboration slow. However, the hindered α-pinene and 2,3-dimethyl-2-butene structures give stable monoalkylboranes very rapidly, with further hydroboration proceeding relatively slowly. The hydroborations can also be carried out in other solvents, such as THF, tert-butyl methyl ether, and n-pentane. A significant rate retardation is observed in dichloromethane. Regioselectivity studies in the hydroboration of 1-hexene, styrene, and allyl chloride with H3B-NPhEtPri in selected solvents were made. The selectivities are similar to those reported for BH3-THF with 1-hexene and styrene, whereas some differences were noted for allyl chloride. The alkylboranes obtained after hydroboration were oxidized with hydrogen peroxide/sodium hydroxide, and the product alcohols were obtained in quantitative yields, as established by GC analysis. The rates and stoichiometry of the reaction of H3B-NPhEtPri in tetrahydrofuran with selected organic compounds containing representative functional groups were examined at room temperature. Simple aldehydes, ketones, carboxylic acids, and aliphatic esters were reduced to the alcohol stage. Acid chlorides, anhydrides, and aromatic carboxylic esters were unreactive under similar conditions. Imines, tertiary amides, and nitriles were reduced to the corresponding amines. However, primary and secondary amides and nitro compounds were not reduced under these conditions. The reduction of esters, amides, and nitriles, which exhibit a sluggish reaction at room temperature, proceeds readily under reflux conditions in tetrahydrofuran and dioxane and also without solvent (at 85-90°C). The carrier amine was recovered by simple acid-base manipulations in good yield and can be readily recycled to make the borane adduct.

A Mild and Convenient Reduction of Aromatic and Heteroaromatic Aldoximes with Ammonium Formate/Pd

Kaczmarek, Lukasz,Balicki, Roman

, p. 695 - 697 (1994)

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The efficient solvent-free reduction of oximes to amines with NaBH3CN catalyzed by ZrCl4/nano Fe3O4 system

Sadighnia, Leila,Zeynizadeh, Behzad

, p. 873 - 878 (2015)

Reduction of various aldoximes and ketoximes to the corresponding amines was carried out easily and efficiently with NaBH3CN in the presence of ZrCl4/nano Fe3O4 system. The reactions were carried out under solvent-free conditions at room temperature or 75-80°C to afford amines in high to excellent yields.

Reductions of aliphatic and aromatic nitriles to primary amines with diisopropylaminoborane

Haddenham, Dustin,Pasumansky, Lubov,DeSoto, Jamie,Eagon, Scott,Singaram, Bakthan

, p. 1964 - 1970 (2009)

Diisopropylaminoborane [BH2Nf)Pr)2] in the presence of a catalytic amount of lithium borohydride (LiBH4) reduces a large variety of aliphatic and aromatic nitriles in excellent yields. BH 2NOPr)2 can be prepared by two methods: first by reacting diisopropylamineborane [(iPr)2N)BH3] with 1.1 equiv of n-butylhthium (n-BuLi) followed by methyl iodide (MeI), or reacting iPrN:BH 3 with 1 equiv of n-BuLi followed by trimethylsilyl chloride (TMSCl). BH2N(ZPr)2 prepared with MeI was found to reduce benzonitriles to the corresponding benzylamines at ambient temperatures, whereas diisopropylaminoborane prepared with TMSCl does not reduce nitriles unless a catalytic amount of a lithium ion source, such as LiBH4 or lithium tetraphenylborate (LiBPh4), is added to the reaction. The reductions of benzonitriles with one or more electron-withdrawing groups on the aromatic ring generally occur much faster with higher yields. For example, 2,4-dichlorobenzonitrile was successfully reduced to 2,4-dichlorobenzylamine in 99% yield after 5 h at 25 °C. On the other hand, benzonitriles containing electron-donating groups on the aromatic ring require refluxing in tetrahydrofuran (THF) for complete reduction. For instance, 4- methoxybenzonitrile was successfully reduced to 4-methoxybenzylamine in 80% yield. Aliphatic nitriles can also be reduced by the BH2N(iPr) 2/cat. LiBH4 reducing system. Benzyl cyanide was reduced to phenethylamine in 83% yield. BH2NOPr)2 can also reduce nitriles in the presence of unconjugated alkenes and alkynes such as the reduction of 2-hexynenitrile to hex-5-yn-l-amine in 80% yield. Unfortunately, selective reduction of a nitrile in the presence of an aldehyde is not possible as aldehydes are reduced along with the nitrile. However, selective reduction of the nitrile group at 25 °C in the presence of an ester is possible as long as the nitrile group is activated by an electron-withdrawing substituent. It should be pointed out that lithium aminoborohydrides (LABs) do not reduce nitriles under ambient conditions and behave as bases with aliphatic nitriles as well as nitriles containing acidic a-protons. Consequently, both LABs and BH2NOPr)2 are complementary to each other and offer methods for the selective reductions of multifunctional compounds.

Reduction of aromatic nitriles into aldehydes using calcium hypophosphite and a nickel precursor

Mouselmani, Rim,Hachem, Ali,Alaaeddine, Ali,Métay, Estelle,Lemaire, Marc

, p. 6600 - 6605 (2018)

Herein we report the reduction of aromatic nitriles into aldehydes with calcium hypophosphite in the presence of base and nickel(ii) complex in a water/ethanol mixture. This catalytic system reduced efficiently a series of aromatic nitriles bearing different functional groups such as -Cl, -CF3, -Br, -CH3, -OCH3, -COOCH2CH3, -OH and -CHO. The corresponding aldehydes were isolated in moderate to excellent yields (30-94%).

Catalytic Activity of Polynuclear Platinum Carbonyl Anions in Homogeneous Hydrogenation Reactions

Bhaduri, Sumit,Sharma, Krishna R.

, p. 727 - 732 (1982)

The homogeneous hydrogenation of benzaldehyde, heptanal, cyclohexanone, cyclohexene, acetonitrile, and benzonitrile has been studied using n4>2 (1) as the catalyst over a range of temperature (40-80 deg C) and pressure (20-64 lbf in-2).Infrared spectroscopic studies suggest the formation of a common intermediate in reactions carried out at >=60 deg C.Benzaldehyde is the most readily hydrogenated; the nature of the products depends on the pressure of hydrogen used and is selective to either benzyl alcohol or a mixture of benzene and methanol.Kinetic studies on the rate of benzyl alcohol formation indicate a first-order dependence of the rate on the concentration of (1).While the rate shows a Michaelis-Menten type of dependence on the PhCHO concentration, it seems to be independent of H2 pressure in the range 20-25 lbf in-2.Under these conditions, a value of 63.81 kJ mol-1 for the activation energy is obtained from the Arrhenius plot.A tentative mechanism for PhCHO hydrogenation is discussed.

A novel, chemoselective and efficient production of amines from azides using ZrCl4/NaBH4

Purushothama Chary,Raja Ram,Salahuddin,Iyengar

, p. 3559 - 3563 (2000)

A practical and cheaper reagent system ZrCl4/NaBH4 is used for the production of amines from azides is described.

Selective Hydrogenation of Nitriles to Primary Amines Catalyzed by a Cobalt Pincer Complex

Mukherjee, Arup,Srimani, Dipankar,Chakraborty, Subrata,Ben-David, Yehoshoa,Milstein, David

, p. 8888 - 8891 (2015)

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.

Pd/C(en) catalyzed chemoselective hydrogenation in the presence of aryl nitriles

Maegawa, Tomohiro,Fujita, Yuki,Sakurai, Ai,Akashi, Akira,Sato, Mutsumi,Oono, Keiji,Sajiki, Hironao

, p. 837 - 839 (2007)

Aromatic nitriles are not only important components of natural products, pharmaceuticals, herbicides and agrochemicals but also a synthetic equivalent of various functionalities. The development of synthetic methods of aromatic nitriles have been increasing in terms of its usefulness. Since aromatic nitriles are susceptible to the hydrogenation, it has been desired for the development of chemoselective hydrogenation method with retention of nitrile groups. Pd/C is one of the most popular catalysts for hydrogenation and many of reducible functional groups such as multiple bonds, benzyl ethers, N-Cbzs, nitro groups and so on could be easily reduced under the conditions. Therefore, it is very difficult to achieve the chemoselective hydrogenation of substrates containing two or more reducible functional groups. We have found that a Pd/C catalyst formed an isolable complex with ethylenediamine (en) employed as catalytic poison, and the complex [Pd/C(en)] catalyzed chemoselective hydrogenation of a variety of reducible functionalities distinguishing O-benzyl, N-Cbz and O-TBDMS protective groups, benzyl alcohols and epoxides. In the course of these investigations, we found the aryl nitriles could survive under the Pd/C(en)-catalyzed hydrogenation conditions in THF whose choice is important for the effective suppression. This methodology could be applied to the selective hydrogenation of alkene and alkyne functionalities in the presence of aromatic nitrile.

Schultz,Gmelin

, p. 342,346 (1954)

Dimethylethylamine-Alane and N-Methylpyrrolidine-Alane. A Convenient Synthesis of Alane, a Useful Selective Reducing Agent in Organic Synthesis

Marlett, Everett M.,Park, Won Suh

, p. 2968 - 2969 (1990)

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An Efficient Ruthenium Catalyst Bearing Tetradentate Ligand for Hydrogenations of Carbon Dioxide

Zhang, Feng-Hua,Liu, Chong,Li, Wei,Tian, Gui-Long,Xie, Jian-Hua,Zhou, Qi-Lin

, p. 1000 - 1002 (2018)

A ruthenium complex with a tetradentate bipyridine ligand was proved to be a highly efficient catalyst for the conversions of CO2. Turnover numbers up to 300 000, 9800, and 2100 were achieved for the hydrogenations of CO2 to formamides, formamides to methanol and amines, and the direct hydrogenation of CO2 to methanol, respectively.

Magnesium-Catalyzed Proficient Reduction of Oximes to Amines Using Ammonium Formate

Abiraj,Gowda, D. Channe

, p. 599 - 605 (2004)

Various aldoximes and ketoximes were selectively reduced to the corresponding amines by catalytic transfer hydrogenation employing low cost magnesium powder and ammonium formate at room temperature. Many other functionalities such as halogens, -OH, -OCH3, -COOH and -CH 3 remained unaffected. The hydrogenation is fast, mild, clean, cost effective and high yielding.

2-(4-Nitrophenyl)-1H-indolyl-3-methyl Chromophore: A Versatile Photocage that Responds to Visible-light One-photon and Near-infrared-light Two-photon Excitations

Abe, Manabu,Guo, Runzhao,Hamao, Kozue,Lin, Qianghua,Takagi, Ryukichi

supporting information, p. 153 - 156 (2022/02/14)

Due to cell damage caused by UV light, photoremovable protecting groups (PPGs) that are removed using visible or near-infrared light are attracting attention. A 2-(4-nitrophenyl)- 1H-indolyl-3-methyl chromophore (NPIM) was synthesized as a novel PPG. Various compounds were caged using this PPG and uncaged using visible or near-infrared light. Low cytotoxicity of NPIM indicates that it may be applied in physiological studies.

Mechanically Strong Heterogeneous Catalysts via Immobilization of Powderous Catalysts to Porous Plastic Tablets

Li, Tingting,Xu, Bo

supporting information, p. 2673 - 2678 (2021/08/03)

Main observation and conclusion: We describe a practical and general protocol for immobilization of heterogeneous catalysts to mechanically robust porous ultra-high molecular weight polyethylene tablets using inter-facial Lifshitz-van der Waals Interactions. Diverse types of powderous catalysts, including Cu, Pd/C, Pd/Al2O3, Pt/C, and Rh/C have been immobilized successfully. The immobilized catalysts are mechanistically robust towards stirring in solutions, and they worked well in diverse synthetic reactions. The immobilized catalyst tablets are easy to handle and reused. Moreover, the metal leaching of immobilized catalysts was reduced significantly.