100-60-7Relevant articles and documents
One pot catalytic NO2 reduction, ring hydrogenation, and N-alkylation from nitroarenes to generate alicyclic amines using Ru/C-NaNO 2
Oh, Seung Geun,Mishra, Vivek,Cho, Jin Ku,Kim, Baek-Jin,Kim, Hoon Sik,Suh, Young-Woong,Lee, Hyunjoo,Park, Ho Seok,Kim, Yong Jin
, p. 79 - 83 (2014)
A report to produce alicyclic amines and subsequent N-alkylation with alcohols using Ru/C-NaNO2 catalyzed facile transformation of nitrobenzene was investigated. Effects of solvent, temperature, pressure, reaction time, and molar-ratio of substrate/catalyst on product composition were also studied. These mechanistic studies explain that nitrobenzene undergoes hydrogenation reaction in the following order; -NO2 reduction to -NH2, aromatic ring-hydrogenation to alicyclic, and from the reaction of alcohol to give N-alkylated amines. This investigation shed lights on possible application to polyurethane chemistry since these amines are used as important precursors for diisocyanates.
Commercial Pd/C-Catalyzed N-Methylation of Nitroarenes and Amines Using Methanol as Both C1 and H2 Source
Goyal, Vishakha,Gahtori, Jyoti,Narani, Anand,Gupta, Piyush,Bordoloi, Ankur,Natte, Kishore
, p. 15389 - 15398 (2019)
Herein, we report commercially available carbon-supported-palladium (Pd/C)-catalyzed N-methylation of nitroarenes and amines using MeOH as both a C1 and a H2 source. This transformation proceeds with high atom-economy and in an environmentally friendly way via borrowing hydrogen mechanism. A total of >30 structurally diverse N-methylamines, including bioactive compounds, were selectively synthesized with isolated yields of up to 95%. Furthermore, selective N-methylation and deuteration of nimesulide, a nonsteroidal anti-inflammatory drug, were realized through the late-stage functionalization.
Dual pathways for the desilylation of silylamines by singlet oxygen
Baciocchi, Enrico,Del Giacco, Tiziana,Lapi, Andrea
, p. 1783 - 1786 (2006)
A kinetic and product study has been carried out for the reactions of silylamines 1a and 1b with 1O2 in MeCN and (80:20) MeCN-MeOH. Indications suggesting an electron-transfer step following exciplex (I) formation have been obtained. However, the fate of the radical cation is solvent dependent. The radical cation undergoes desilylation in MeCN-MeOH and deprotonation in MeCN.
Identification of Novel Bacterial Members of the Imine Reductase Enzyme Family that Perform Reductive Amination
France, Scott P.,Howard, Roger M.,Steflik, Jeremy,Weise, Nicholas J.,Mangas-Sanchez, Juan,Montgomery, Sarah L.,Crook, Robert,Kumar, Rajesh,Turner, Nicholas J.
, p. 510 - 514 (2018)
Reductive amination of carbonyl compounds constitutes one of the most efficient ways to rapidly construct chiral and achiral amine frameworks. Imine reductase (IRED) biocatalysts represent a versatile family of enzymes for amine synthesis through NADPH-mediated imine reduction. The reductive aminases (RedAms) are a subfamily of IREDs that were recently shown to catalyze imine formation as well as imine reduction. Herein, a diverse library of novel enzymes were expressed and screened as cell-free lysates for their ability to facilitate reductive amination to expand the known suite of biocatalysts for this transformation and to identify more enzymes with potential industrial applications. A range of ketones and amines were examined, and enzymes were identified that were capable of accepting benzylamine, pyrrolidine, ammonia, and aniline. Amine equivalents as low as 2.5 were employed to afford up to >99 % conversion, and for chiral products, up to >98 % ee could be achieved. Preparative-scale reactions were conducted with low amine equivalents (1.5 or 2.0) of methylamine, allylamine, and pyrrolidine, achieving up to >99 % conversion and 76 % yield.
Electrocatalytic Dealkylation of Amines Mediated by Ferrocene
Torriero, Angel A. J.,Morda, Joanne,Saw, Jessica
, p. 4280 - 4287 (2019)
The homogeneous catalytic oxidation of dicyclohexylamine (DCHA), N,N-dimethylcyclohexylamine (DMCHA) and N,N-dicyclohexylmethylamine (DCHMA) has been investigated in the presence of electrochemically generated ferrocenium ions as the catalyst. Mechanistic details for this electrocatalytic process have been scrutinized with the use of cyclic voltammetry, bulk electrolysis, and digital simulations techniques. A one-electron catalytic process between ferrocene and the respective amines was observed. The products obtained from bulk electrolysis were isolated and identified by FTIR, 1H and 13C NMR spectroscopy, and mass spectrometry. Both DCHMA and DMCHA proceed to yield a secondary amine product by the elimination of one methyl group. In the absence of this group, as in the case of DCHA, the cycloalkyl group is then eliminated. The catalytic efficiency and the second-order rate constants were estimated and found to follow the order DCHA ≤ DMCHA DCHMA. The results presented in this work should open up a new avenue to achieve simple, low-cost, and efficient amine oxidation, which could be useful in several areas of chemistry.
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Blicke,Lu
, p. 3933 (1952)
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A New and Specific Method for the Monomethylation of Primary Amines
Barluenga, Jose,Bayon, Ana M.,Asensio, Gregorio
, p. 1334 - 1335 (1984)
The reduction of monomeric methyleneamines, representing a convenient and highly specific procedure for the title reaction, is studied.
Mechanistic Studies on the Role of Carbon Dioxide in the Synthesis of Methylcarbamates from Amines and Dimethylcarbonate in the Presence of CO2
Aresta, Michele,Quaranta, Eugenio
, p. 9489 - 9502 (1991)
N-Alkylmethylcarbamates have been synthesized from amines and dimethylcarbonate (DMC) in the presence of carbon dioxide.The catalytic role of CO2 in the overall process has been investigated and elucidated.Key words: carbon dioxide; organic carbamates; dimethylcarbonate; carbamic-carbonic anhydride
Synthesis of methyl carbamates from primary aliphatic amines and dimethyl carbonate in supercritical CO2: Effects of pressure and cosolvents and chemoselectivity
Selva, Maurizio,Tundo, Pietro,Perosa, Alvise,Dall'Acqua, Federico
, p. 2771 - 2777 (2005)
(Chemical Equation Presented) At 130 °C, in the presence of CO 2 (5-200 bar), primary aliphatic amines react with dimethyl carbonate (MeOCO2Me, DMC) to yield methyl carbamates (RNHCO2Me) and N-methylation side-products (RNHMe and RNMe2). The pressure of CO2 largely influences both the reaction conversion and the selectivity toward urethanes: in general, conversion goes through a maximum (70-80%) in the midrange (40 bar) and drops at lower and higher pressures, whereas selectivity is continuously improved (from 50% up to 90%) by an increase of the pressure. This is explained by the multiple role of CO2 in (i) the acid/base equilibrium with aliphatic amines, (ii) the reactivity/solubility of RNHCO2- nucleophiles with/in DMC, and (iii) the inhibition of competitive N-methylation reaction of the substrates. Cosolvents also affect the reaction: in particular, a drop in selectivity is observed with polar protic media (i.e., MeOH), plausibly because of solvation effects (through H-bonds) of RNHCO2- moieties. The reaction shows also a good chemoselectivity: bifunctional aliphatic amines bearing either aromatic NH2 or OH substituents [XC6H4(CH2)nNH2, X = NH2, OH; n = 1 2], undergo methoxycarbonylation reactions exclusively at aliphatic amino groups and give the corresponding methyl carbamates [XC 6H4(CH2)nNHCO2Me] in 39-65% isolated yields.
Fluoride-Catalyzed Methylation of Amines by Reductive Functionalization of CO2with Hydrosilanes
Liu, Xiao-Fang,Ma, Ran,Qiao, Chang,Cao, Han,He, Liang-Nian
, p. 16489 - 16493 (2016)
An effective and inexpensive organocatalyst tetrabutylammonium fluoride (TBAF) was developed for the reductive functionalization of CO2with amines to selectively afford formamides or methylamines by employing hydrosilanes. Hydrosilanes with different substituents show discriminatory reducing activity. Thus, the formation of formamides and further reduction products, that is, methylamines could be controlled by elegantly tuning hydrosilane types. Formamides were obtained exclusively under an atmospheric pressure of CO2with triethoxysilane. Using phenylsilane as a reductant, methylamines were attained with up to 99 % yield at 50 °C coupled to a complete deoxygenation of CO2. The crucial intermediate silyl formate in the formylation step was identified and thereby a tentative mechanism involving the fluoride-promoted hydride transfer from the hydrosilane to CO2/formamide was proposed. Striking features of this metal-free protocol are formylation and methylation of amines by reductive functionalization of CO2with hydrosilanes and mild reaction conditions.
Transition Metal-catalysed N-Alkylation of Amines by Alcohols
Grigg, R.,Mitchell, T. R. B.,Sutthivaiyakit, S.,Tongpenyai, N.
, p. 611 - 612 (1981)
Primary and secondary alcohols effect alkylation of primary and secondary amines in the presence of rhodium, iridium, and ruthenium compounds at = 100 deg C, whereby selective monoalkylation of primary amines can be achieved, and heterocyclic rings can be constructed by both inter- and intra-molecular processes.
Continuous reductions and reductive aminations using solid NaBH4
Gilmore, Kerry,Vukeli, Stella,McQuade, D. Tyler,Koksch, Beate,Seeberger, Peter H.
, p. 1771 - 1776 (2014)
Most successful reactions carried out under continuous flow conditions mix homogeneous solutions yielding homogeneous products. Using solids is avoided to prevent pump and reactor clogging; even though solid reagents may often be the best choice for a given transformation. Here we demonstrate that by pumping aldehydes, ketones, or in situ formed imines through a specially formulated NaBH4 column results in efficient reductions. The column design and performance characteristics, along with substrate scope, are discussed.
Photon-initiated heterogeneous redox couples for methylation of anilines under mild conditions
Zhang, Bing,Gao, Hua,Wang, Wei
, p. 4433 - 4437 (2020)
Methylation of anilines has drawn a lot of attention due to their valuable applications and directly using methanol as a methylation reagent is of great advantage. Photon-initiated heterogeneous catalysis of this methylation process meets the requirements of green chemistry. Herein we show that balanced redox zones within carbon nitride supported Pd nanoparticles boost the selectivity of methylation of anilines under mild conditions.
AlCl3 immobilized on silicic acid as efficient Lewis acid catalyst for highly selective preparation of dicyclohexylamine from the vapor phase hydroamination of cyclohexene with cyclohexylamine
Ai, Qiuhong,Jian, Jian,Liu, Pingle,Luo, He'an,Wen, Jingbin,You, Kuiyi,Zhao, Fangfang
, (2020)
An efficient and stable Lewis acid catalyst silicic acid (SA)-immobilized AlCl3 (AlCl3-SA) has been successfully prepared by the chemical bonding method in this work. The results indicated that the immobilized 15percentAlCl3-SA exhibited excellent catalytic performance and stability in the vapor phase hydroamination of cyclohexene with cyclohexylamine. 58.5percent cyclohexene conversion with 98.7percent selectivity to dicyclohexylamine was still maintained after running for over 150 h, and the space time yield of dicyclohexylamine was 142.6 mol/h·m3. The developed AlCl3-SA catalyst had the advantages of low cost and long-time stable activity. Maybe this work provides a promising approach for hydroamination of olefins to amines.
tert-Butoxy-Radical-Promoted α-Arylation of Alkylamines with Aryl Halides
Ueno, Ryota,Ikeda, Yuko,Shirakawa, Eiji
, p. 4188 - 4193 (2017)
In the presence of a tert-butoxy radical precursor, the reaction of alkylamines with aryl halides was found to give α-arylated alkylamines through homolytic aromatic substitution of the halogen atoms.
Electronically tuneable orthometalated RuII–NHC complexes as efficient catalysts for C–C and C–N bond formations via borrowing hydrogen strategy
Illam, Praseetha Mathoor,Rit, Arnab
, p. 67 - 74 (2022/01/19)
The catalytic activities of a series of simple and electronically tuneable cyclometalated RuII–NHC complexes (2a–d) were explored in various C–C/N bond formations following the borrowing hydrogen process. Slight modifications in the ligand backbone were noted to tune the activities of these complexes. Among them, the complex 2d featuring a 1,2,4-triazolylidene donor with a 4-NO2–phenyl substituent displayed the highest activity for the coupling of diverse secondary and primary alcohols with a low catalyst loading of 0.01 mol% and a sub-stoichiometric amount of inexpensive KOH base. The efficacy of this simple system was further showcased in the challenging one-pot unsymmetrical double alkylation of secondary alcohols using different primary alcohols. Moreover, the complex 2d also effectively catalyses the selective mono-N-methylation of various aromatic and aliphatic primary amines using methanol to deliver a range of N-methyl amines. Mechanistically, the β-alkylation reaction follows a borrowing hydrogen pathway which was established by the deuterium labelling experiment in combination with various control experiments. Intriguingly, in situ1H NMR and ESI-MS analyses evidently suggested the involvement of a Ru–H species in the catalytic cycle and further, the kinetic studies revealed a first order dependence of the reaction rate on the catalyst as well as the alcohol concentrations.
