102-05-6Relevant articles and documents
Enhancing the Catalytic Properties of Ruthenium Nanoparticle-SILP Catalysts by Dilution with Iron
Luska, Kylie L.,Bordet, Alexis,Tricard, Simon,Sinev, Ilya,Grünert, Wolfgang,Chaudret, Bruno,Leitner, Walter
, p. 3719 - 3726 (2016)
The partial replacement of ruthenium by iron ("dilution") provided enhanced catalytic activities and selectivities for bimetallic iron-ruthenium nanoparticles immobilized on a supported ionic liquid phase (FeRuNPs@SILP). An organometallic synthetic approach to the preparation of FeRuNPs@SILP allowed for a controlled and flexible incorporation of Fe into bimetallic FeRu NPs. The hydrogenation of substituted aromatic substrates using bimetallic FeRuNPs@SILP showed high catalytic activities and selectivities for the reduction of a variety of unsaturated moieties without saturation of the aromatic ring. The formation of a bimetallic phase not only leads to an enhanced differentiation of the hydrogenation selectivity, but even reversed the order of functional group hydrogenation in certain cases. In particular, bimetallic FeRuNPs@SILP (Fe:Ru = 25:75) were found to exhibit accelerated reaction rates for C=O hydrogenation within furan-based substrates which were >4 times faster than monometallic RuNPs@SILP. Thus, the controlled incorporation of the non-noble metal into the bimetallic phase provided novel catalytic properties that could not be obtained using either of the monometallic catalysts.
Bifunctional (cyclopentadienone)iron-tricarbonyl complexes: Synthesis, computational studies and application in reductive amination
Moulin, Solenne,Dentel, Helene,Pagnoux-Ozherelyeva, Anastassiya,Gaillard, Sylvain,Poater, Albert,Cavallo, Luigi,Lohier, Jean-Francois,Renaud, Jean-Luc
, p. 17881 - 17890 (2013)
Reductive amination under hydrogen pressure is a valuable process in organic chemistry to access amine derivatives from aldehydes or ketones. Knoelker's complex has been shown to be an efficient iron catalyst in this reaction. To determine the influence of the substituents on the cyclopentadienone ancillary ligand, a series of modified Knoelker's complexes was synthesised and fully characterised. These complexes were also transformed into their analogous acetonitrile iron-dicarbonyl complexes. Catalytic activities of these complexes were evaluated and compared in a model reaction. The scope of this reaction is also reported. For mechanistic insights, deuterium-labelling experiments and DFT calculations were undertaken and are also presented. Festival of amination: Two series of modified Knoelker's complexes were synthesised and applied in the reductive amination of various carbonyl derivatives with primary or secondary amines (see scheme, TIPS = triisopropylsilyl). For a mechanistic insight, deuterium-labelling experiments and DFT calculations were undertaken and are also presented. Copyright
Synthesis of Amines via Carbon-Sulfur Bond Cleavages of Substituted Aminomethyl Sulfides with Organolithium Reagents: Aminocarbene Route to Enamines and Sterically Hindered Amines
Eisch, John J.,McNulty, John F.,Shi, Xian
, p. 7 - 9 (1994)
N-Substituted and N,N-disubstituted aminomethyl sulfides can be converted into secondary and tertiary amines, respectively, by organolithium reagents in high yields, regardless of whether the N-substituent is alkyl or aryl; for the former case, imines, and for the latter case, aminocarbenes, are the most likely intermediates.
Fluorocarbon accelerated supported transformations (FAST) on REM resin
Morphy,Rankovic, Zoran,York, Mark
, p. 7509 - 7511 (2001)
The use of perfluorous organic solvents in the solid-phase synthesis of 3° amines on REM resin allows a large reduction in both reaction time and the amount of amine required for a successful Michael reaction. Yields of products were typically at least three fold greater than those observed with standard solvents under the same conditions.
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Pine,Sanchez
, p. 829 (1971)
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A new method for generation of non-stabilized α-amino-substituted carbanions by the reaction of magnesium carbenoids with N-lithio arylamines: their reactivity and a new synthesis of α-amino acid derivatives
Satoh, Tsuyoshi,Osawa, Atsushi,Ohbayashi, Tohru,Kondo, Atsushi
, p. 7892 - 7901 (2006)
Magnesium carbenoids were generated from aryl 1-chloroalkyl sulfoxides with i-PrMgCl in THF at low temperature in quantitative yields. The magnesium carbenoids were found to be reactive with N-lithio alkylamines to afford an olefin, which was derived from dimerization of the magnesium carbenoid, in moderate yield. On the other hand, reaction of the magnesium carbenoids with N-substituted N-lithio arylamines gave non-stabilized α-amino-substituted carbanions in good yields. Reactivity of the α-amino-substituted carbanions with some electrophiles was investigated and it was found that ethyl chloroformate reacted to give α-amino acid derivatives in good yields. As a whole, a new method for one-pot, three-component combined synthesis of α-amino acid derivatives from aryl 1-chloroalkyl sulfoxides was realized.
Alcohol amination with heterogeneous ruthenium hydroxyapatite catalysts
Peeters, Annelies,Claes, Laurens,Geukens, Inge,Stassen, Ivo,De Vos, Dirk
, p. 191 - 197 (2014)
The intermolecular amination of alcohols was performed with ruthenium (Ru3+) immobilized on a calcium hydroxyapatite support. No additional base additives were necessary, nor did the catalyst require base treatment prior to reaction. High conversions were obtained with different amine and alcohol reactants.
Reductive amination without an external hydrogen source
Chusov, Denis,List, Benjamin
, p. 5199 - 5201 (2014)
A method of reductive amination without an external hydrogen source is reported. Carbon monoxide is used as the reductant. The reaction proceeds efficiently for a variety of carbonyl compounds and amines at low catalyst loadings and is mechanistically interesting as it does not seem to involve molecular hydrogen. Look, no H2! Reductive amination without an external hydrogen source has been developed using carbon monoxide as the reductant and rhodium acetate (0.2-1mol %) as catalyst. The method tolerates a variety of functional groups and provides target amines in good to excellent yields.
Reusable supported ruthenium catalysts for the alkylation of amines by using primary alcohols
Peishan, Siah,Dang, Tuan Thanh,Seayad, Abdul Majeed,Ramalingam, Balamurugan
, p. 808 - 814 (2014)
Efficient and recyclable ruthenium catalysts were synthesized from readily available polystyrene-or silica-supported phosphine ligands. Catalysts bound to the polymer support through an ether linkage showed good to excellent activity towards the N-alkylation of primary and secondary amines to afford the alkylated products in 62-99 % yield at 120-140°C. The supported phosphine ligand/ruthenium ratio was found to be crucial for higher catalytic activity and lower ruthenium leaching. The continuous flow N-alkylation of amines was demonstrated by using the supported catalyst in a column reactor. By adopting the hydrogen-borrowing strategy, the synthesis of the anti-Parkinson agent Piribedil was established in 98 % yield at 140°C. Support group steals the show: An efficient Ru-based heterogeneous catalyst from readily available supported phosphine ligands is developed. The nature of the linkage and the extent of ruthenium incorporation are crucial in determining the catalytic activity. The catalyst can be recycled and used under continuous flow in a packed-bed reactor. The alkylation of cyclic amines is achieved in excellent yield at moderate temperatures in the absence of any external base.
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Snyder et al.
, p. 1301,1304 (1954)
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Ruthenium-catalyzed reductive methylation of imines using carbon dioxide and molecular hydrogen
Beydoun, Kassem,Ghattas, Ghazi,Thenert, Katharina,Klankermayer, Jürgen,Leitner, Walter
, p. 11010 - 11014 (2015)
The use of the well-defined [Ru(triphos)(tmm)] catalyst, CO2 as C1 source, and H2 as reducing agent enabled the reductive methylation of isolated imines, as well as the direct coupling of amines with aldehydes and the subsequent reductive methylation of the insitu formed imines. The method, which afforded the corresponding N-methyl amines in very good to excellent yields, was also used for the preparation of the antifungal agent butenafine in one step with no apparent waste, thus increasing the atom efficiency of its synthesis.
Hydrosilylative Reduction of Tertiary Amides to Amines Catalyzed by N-(Phosphinoaryl)anilido Complexes of Iron and Cobalt
Hale, Dylan J.,Murphy, Luke J.,McDonald, Robert,Ferguson, Michael J.,Turculet, Laura
, p. 3818 - 3827 (2019)
The synthesis and structural characterization of low-coordinate Fe(II) and Co(II) complexes supported by the monoanionic P,N-ligand N-(2-dicyclohexylphosphinophenyl)-2,6-diisopropylanilide are described. A three-coordinate (P,N)Fe-hexamethyldisilazide complex (2), and four-coordinate (P,N)Fe- (3-Fe) and (P,N)Co-alkyl (3-Co) complexes were evaluated as pre-catalysts for the hydrosilylative reduction of amides with PhSiH3 (5 mol % pre-catalyst, 1 equiv. PhSiH3, 80 °C, 1–24 h). The Fe complex 2 proved to be more broadly effective for the reduction of a variety of tertiary amide substrates, and was shown to mediate the reduction of N,N-dibenzylbenzamide at a loading of 1 mol %, to achieve near quantitative formation of tribenzylamine in 1 h (80 °C). Complex 2 also proved effective for the hydrosilylation of tertiary amides under ambient conditions (5 mol % Fe, 24 h), which is a unique example of room temperature amide hydrosilylation mediated by an Fe catalyst without the need for photochemical activation. Given the widespread use of amide reduction protocols in synthesis, the development of efficient Fe-based catalysts that operate under mild conditions is an important target.
Expanding the Ligand Framework Diversity of Carbodicarbenes and Direct Detection of Boron Activation in the Methylation of Amines with CO2
Chen, Wen-Ching,Shen, Jiun-Shian,Jurca, Titel,Peng, Chun-Jung,Lin, Yen-Hsu,Wang, Yi-Ping,Shih, Wei-Chih,Yap, Glenn P. A.,Ong, Tiow-Gan
, p. 15207 - 15212 (2015)
A simple and convergent synthetic strategy used to increase the diversity of the carbodicarbene ligand framework through incorporation of unsymmetrical pendant groups is reported. Structural analysis and spectroscopic studies of ligands and their Rh complexes are reported. Reactivity studies reveal carbodicarbenes as competent organocatalysts for amine methylation using CO2 as a synthon. A unique B-H-activated boron-carbodicarbene complex was isolated as a reaction intermediate, providing mechanistic insight into the CO2 functionalization process.
Water-Soluble Iridium N-Heterocyclic Carbene Complexes for the Alkylation of Amines with Alcohols
Fernandes, Ana,Royo, Beatriz
, p. 3912 - 3917 (2017)
A new series of water-soluble Ir complexes with N-heterocyclic carbene ligands that bear ester and amide groups has been obtained and fully characterized. The new complexes are highly reactive and selective for the alkylation of amines with alcohols with a 1:1 ratio of reactants in water and in the absence of base or other additives. The catalytic system has a broad substrate scope, which allows the synthesis of a variety of primary and secondary amines in excellent yields. A tolerance to a large range of functional groups was obtained.
Titanium(IV) Isopropoxide and Sodium Borohydride: A Reagent of Choice for Reductive Amination
Bhattacharyya, Sukanta
, p. 2401 - 2404 (1994)
The preliminary results on the novel use of titanium(IV) isopropoxide and sodium borohydride in reductive amination reactions are reported.A highly efficient and mild procedure for reductive aminations of formaldehyde with a variety of primary and secondary amines is described.
Preparation of (aminomethyl)stannanes by reduction of α-amidoorgano stannanes
Burchat, Andrew F.,Chong, J. Michael,Nielsen, Nathan
, p. 7627 - 7630 (1996)
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Metal-free reduction of secondary and tertiary N-phenyl amides by tris(pentafluorophenyl)boron-catalyzed hydrosilylation
Chadwick, Ryan C.,Kardelis, Vladimir,Lim, Philip,Adronov, Alex
, p. 7728 - 7733 (2014)
Tris(pentafluorophenyl)boron B(C6F5)3 is an effective catalyst for the hydrosilylative reduction of tertiary and N-phenyl secondary amides. It allows for the mild reduction of a variety of these amides in near quantitative yield, with minimal purification, at low temperatures, and with short reaction times. This reduction shows functional group tolerance for alkenes, nitro groups, and aryl halides, including aryl iodides.
Carbon Dioxide Reduction to Methylamines under Metal-Free Conditions
Blondiaux, Enguerrand,Pouessel, Jacky,Cantat, Thibault
, p. 12186 - 12190 (2014)
The first metal-free catalysts are reported for the methylation of amines with carbon dioxide. Proazaphosphatrane superbases prove to be highly active catalysts in the reductive functionalization of CO2, in the presence of hydroboranes. The new methodology enables the methylation of N-H bonds in a wide variety of amines, including secondary amines, with increased chemoselectivity. Organocatalysis: Proazaphosphatrane superbases prove to be highly active catalysts in the reductive functionalization of CO2, in the presence of hydroboranes. The new method makes possible the methylation of N-H bonds in a wide variety of amines, including secondary amines (see picture), with increased chemoselectivity.
Biomass-derived N-doped porous carbon: An efficient metal-free catalyst for methylation of amines with CO2
Tang, Feiying,Wang, Liqiang,Liu, You-Nian
, p. 6252 - 6257 (2019)
Developing green, efficient, and low-cost catalysts for methylation of N-H by using CO2 as the C1 resource is highly desired yet remains a significant challenge. Herein, N-doped porous carbons (NPCs) were designed, synthesized, and proved to be an excellent metal-free catalyst for CO2-participated methylation conversion. NPCs were prepared via the pyrolysis of a mixture of tannic acid and urea. Both theoretical calculation and experiment demonstrate that the N species especially pyridinic N and pyrrolic N within NPCs can work as Lewis basic sites for attacking CO2 to weaken the CO bonds and lower the molecule conversion barrier, facilitating the subsequent methylation of N-H to produce, for example, N,N-dimethylaniline. Besides, the unique porous structure can enrich CO2 and accelerate mass transfer, synergistically promoting the conversion of CO2. The optimized NPC(1/5) catalyst, integrating the porous structure and strong Lewis basicity, exhibits excellent catalytic activity for CO2-based methylation reaction under mild conditions (1 bar CO2, 75 °C). Our work, for the first time, demonstrates the feasibility of using NPCs to catalyze the methylation of amino compounds to produce N,N-dimethylamine by exploiting CO2 as the C1 resource.
Simplified preparation of a graphene-co-shelled Ni/NiO@C nano-catalyst and its application in theN-dimethylation synthesis of amines under mild conditions
Liu, Jianguo,Ma, Longlong,Song, Yanpei,Zhang, Mingyue,Zhuang, Xiuzheng
supporting information, p. 4604 - 4617 (2021/06/30)
The development of Earth-abundant, reusable and non-toxic heterogeneous catalysts to be applied in the pharmaceutical industry for bio-active relevant compound synthesis remains an important goal of general chemical research.N-methylated compounds, as one of the most essential bioactive compounds, have been widely used in the fine and bulk chemical industries for the production of high-value chemicals. Herein, an environmentally friendly and simplified method for the preparation of graphene encapsulated Ni/NiO nanoalloy catalysts (Ni/NiO@C) was developed for the first time, for the highly selective synthesis ofN-methylated compounds using various functional amines and aldehydes under easy to handle, and industrially applicable conditions. A large number of primary and secondary amines (more than 70 examples) could be converted to the correspondingN,N-dimethylamines with the participation of different functional aldehydes, with an average yield of over 95%. A gram-scale synthesis also demonstrated a similar yield when compared with the benchmark test. In addition, it was further proved that the catalyst could easily be recycled because of its intrinsic magnetism and reused up to 10 times without losing its activity and selectivity. Also, for the first time, the tandem synthesis ofN,N-dimethylamine products in a one-pot process, using only a single earth-abundant metal catalyst, whose activity and selectivity were more than 99% and 94%, respectively, for all tested substrates, was developed. Overall, the advantages of this newly developed method include operational simplicity, high stability, easy recyclability, cost-effectiveness of the catalyst, and good functional group compatibility for the synthesis ofN-methylation products as well as the industrially applicable tandem synthesis process.
Discriminating non-ylidic carbon-sulfur bond cleavages of sulfonium ylides for alkylation and arylation reactions
Cai, Lei,Chen, Qi,Fang, Jing,Li, Ting,Liao, Zhiwen,Ma, Xiang,Meng, Lingkui,Sun, Jiuchang,Wan, Qian,Zeng, Jing
, (2021/07/25)
A sulfonium ylide participated alkylation and arylation under transition-metal free conditions is described. The disparate reaction pattern allowed the separate activation of non-ylidic S-alkyl and S-aryl bond. Under acidic conditions, sulfonium ylides serve as alkyl cation precursors which facilitate the alkylations. While under alkaline conditions, cleavage of non-ylidic S-aryl bond produces O-arylated compounds efficiently. The robustness of the protocols were established by the excellent compatibility of wide variety of substrates including carbohydrates.
Hydrosilylative reduction of primary amides to primary amines catalyzed by a terminal [Ni-OH] complex
Bera, Jitendra K.,Pandey, Pragati
, p. 9204 - 9207 (2021/09/20)
A terminal [Ni-OH] complex1, supported by triflamide-functionalized NHC ligands, catalyzes the hydrosilylative reduction of a range of primary amides into primary amines in good to excellent yields under base-free conditions with key functional group tolerance. Catalyst1is also effective for the reduction of a variety of tertiary and secondary amides. In contrast to literature reports, the reactivity of1towards amide reduction follows an inverse trend,i.e., 1° amide > 3° amide > 2° amide. The reaction does not follow a usual dehydration pathway.
