- Scope and limitations of reductive amination catalyzed by half-sandwich iridium complexes under mild reaction conditions
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The conversion of aldehydes and ketones to 1° amines could be promoted by half-sandwich iridium complexes using ammonium formate as both the nitrogen and hydride source. To optimize this method for green chemical synthesis, we tested various carbonyl substrates in common polar solvents at physiological temperature (37 °C) and ambient pressure. We found that in methanol, excellent selectivity for the amine over alcohol/amide products could be achieved for a broad assortment of carbonyl-containing compounds. In aqueous media, selective reduction of carbonyls to 1° amines was achieved in the absence of acids. Unfortunately, at Ir catalyst concentrations of 1 mM in water, reductive amination efficiency dropped significantly, which suggest that this catalytic methodology might be not suitable for aqueous applications where very low catalyst concentration is required (e.g., inside living cells).
- Nguyen, Dat P.,Sladek, Rudolph N.,Do, Loi H.
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supporting information
(2020/07/15)
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- Ultra-small cobalt nanoparticles from molecularly-defined Co-salen complexes for catalytic synthesis of amines
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We report the synthesis of in situ generated cobalt nanoparticles from molecularly defined complexes as efficient and selective catalysts for reductive amination reactions. In the presence of ammonia and hydrogen, cobalt-salen complexes such as cobalt(ii)-N,N′-bis(salicylidene)-1,2-phenylenediamine produce ultra-small (2-4 nm) cobalt-nanoparticles embedded in a carbon-nitrogen framework. The resulting materials constitute stable, reusable and magnetically separable catalysts, which enable the synthesis of linear and branched benzylic, heterocyclic and aliphatic primary amines from carbonyl compounds and ammonia. The isolated nanoparticles also represent excellent catalysts for the synthesis of primary, secondary as well as tertiary amines including biologically relevant N-methyl amines.
- Beller, Matthias,Chandrashekhar, Vishwas G.,Gawande, Manoj B.,Jagadeesh, Rajenahally V.,Kalevaru, Narayana V.,Kamer, Paul C. J.,Senthamarai, Thirusangumurugan,Zbo?il, Radek
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p. 2973 - 2981
(2020/03/27)
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- Reusable Nickel Nanoparticles-Catalyzed Reductive Amination for Selective Synthesis of Primary Amines
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The preparation of nickel nanoparticles as efficient reductive amination catalysts by pyrolysis of in situ generated Ni-tartaric acid complex on silica is presented. The resulting stable and reusable Ni-nanocatalyst enables the synthesis of functionalized and structurally diverse primary benzylic, heterocyclic and aliphatic amines starting from inexpensive and readily available carbonyl compounds and ammonia in presence of molecular hydrogen. Applying this Ni-based amination protocol, -NH2 moiety can be introduced in structurally complex compounds, for example, steroid derivatives and pharmaceuticals.
- Murugesan, Kathiravan,Beller, Matthias,Jagadeesh, Rajenahally V.
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supporting information
p. 5064 - 5068
(2019/03/19)
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- Platinum-(phosphinito-phosphinous acid) complexes as bi-talented catalysts for oxidative fragmentation of piperidinols: An entry to primary amines
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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
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p. 37825 - 37829
(2019/12/03)
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- Palladium-Catalyzed α-Arylation of Silylenol Ethers in the Synthesis of Isoquinolines and Phenanthridines
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A diverse array of isoquinolines and phenanthridines have been accessed by developing a two-step, one-pot method constituting regioselective palladium-catalyzed Kuwajima-Urabe α-arylation of silylenol ethers and acid-mediated deprotection, annulation, and aromatization. Structural diversity in the silylenol ethers leads to three different classes of isoquinolines and phenanthridines from which related natural products can be derived. The synthetic utility of this method by the quick assembly of the natural product trispheridine is also demonstrated.
- Saini, Gaurav,Kumar, Pravin,Kumar, Gangam Srikanth,Mangadan, Arun Raj Kizhakkayil,Kapur, Manmohan
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supporting information
p. 441 - 444
(2018/01/28)
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- MOF-derived cobalt nanoparticles catalyze a general synthesis of amines
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The development of base metal catalysts for the synthesis of pharmaceutically relevant compounds remains an important goal of chemical research. Here, we report that cobalt nanoparticles encapsulated by a graphitic shell are broadly effective reductive amination catalysts. Their convenient and practical preparation entailed template assembly of cobaltdiamine- dicarboxylic acid metal organic frameworks on carbon and subsequent pyrolysis under inert atmosphere.The resulting stable and reusable catalysts were active for synthesis of primary, secondary, tertiary, and N-methylamines (more than 140 examples).The reaction couples easily accessible carbonyl compounds (aldehydes and ketones) with ammonia, amines, or nitro compounds, and molecular hydrogen under industrially viable and scalable conditions, offering cost-effective access to numerous amines, amino acid derivatives, and more complex drug targets.
- Jagadeesh, Rajenahally V.,Murugesan, Kathiravan,Alshammari, Ahmad S.,Neumann, Helfried,Pohl, Marga-Martina,Radnik, J?rg,Beller, Matthias
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p. 326 - 332
(2017/09/28)
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- A method for the production of primary amines
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The invention relates to the field of chemical industry and particularly relates to a method for preparing primary amine by using the raw materials including halogenated hydrocarbon (or hydrocarbon alcohol sulfonate) and ammonia water (or formamide). The method comprises the following three steps: (1) imidization: 3,4-diarylfuran-2,5-diketone (I) reacts with ammonia (or formamide) and the like to obtain 3,4-diaryl-1H-pyrrole-2,5-diketone (II); (2) N-hydrocarbylation: 3,4-diaryl-1H-pyrrole-2,5-diketone (II) generates an N-hydrocarbylation reaction with halogenated hydrocarbon (or hydrocarbon alcohol sulfonate) in the presence of alkali to obtain N-hydrocarbyl-3,4-diaryl-1H-pyrrole-2,5-diketone (III); and (3) hydrolysis: N-hydrocarbyl-3,4-diaryl-1H-pyrrole-2,5-diketone (III) is subjected to alkali hydrolysis to obtain primary amine and the generated 2,3-diaryl maleate is subjected to acid treatment and automatic ring closing to form 3,4-diaryl furan-2,5-diketone (I) which is subjected to imidization and directly applied to the N-hydrocarbylation reaction. The method provided by the invention has the characteristics that the 3,4-diaryl furan-2,5-diketone can be circularly used at a high recovery rate, the molar ratio of the raw materials is low, and the yield of the product primary amine is high.
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Paragraph 0207
(2016/10/09)
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- CuI-catalyzed coupling of gem-dibromovinylanilides and sulfonamides: An efficient method for the synthesis of 2-amidoindoles and indolo[1,2-a] quinazolines
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A Cu(I)-catalyzed, intermolecular protocol for the synthesis of 2-amidoindoles and tetrahydroindolo[1,2-a]quinazolines in shorter time and high yields is reported. The key highlight of this disclosure is the formation of 2-amidoindole and tetrahydroindolo[1,2-a]quinazoline moieties directly from gem-dibromovinylanilides and sulfonamides in a one-pot fashion through the in situ formation of ynamides followed by a base-promoted intramolecular hydroamidation.
- Kiruthika, Selvarangam E.,Perumal, Paramasivan Thirumalai
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supporting information
p. 484 - 487
(2014/04/03)
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- Fe3O4-SiO2-P4VP pH-sensitive microgel for immobilization of nickel nanoparticles: An efficient heterogeneous catalyst for nitrile reduction in water
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Fe3O4 magnetic nanoparticles (MNPs) were modified with (3-aminopropyl)triethoxysilane through silanization. An atom transfer radical polymerization-initiating site immobilized onto amine-functionalized Fe3O4 MNPs. The surface-initiated atom transfer radical polymerization of 4-vinylpyridine was then performed in the presence of Fe 3O4-SiO2-Br nanoparticles, which led to the formation of Fe3O4-SiO2-P4VP [P4VP=poly(4-vinylpyridine)] hybrid microgels cross-linked with Fe 3O4 MNPs. Our approach uses polymer microgels as templates for the synthesis of nickel nanoparticles (NiNPs). The tunable properties of synthesized NiNPs@Fe3O4-SiO2-P4VP pH-sensitive microgels were used in the catalytic reduction of aliphatic and aromatic nitriles. Moreover, the catalytic activity of metal nanocomposites that can be modulated by the volume transition of microgel structures with changing pH has been evaluated. TEM, X-ray photoelectron spectroscopy, thermogravimetric analysis, atomic absorption spectroscopy, XRD, UV/Vis spectroscopy, and FTIR spectroscopy were used to characterize the resultant catalyst. Mystery solved: Our approach uses polymer microgels as templates for the synthesis of nickel nanoparticles. The tunable properties of synthesized NiNPs@Fe3O 4-SiO2-P4VP [NiNPs=nickel nanoparticles; P4VP=poly(4-vinylpyridine)] pH-sensitive microgels are used in the catalytic reduction of aliphatic and aromatic nitriles. Moreover, the catalytic activity of metal nanocomposites that can be modulated by the volume transition of microgel structures with changing pH has been evaluated. Copyright
- Nabid, Mohammad Reza,Bide, Yasamin,Niknezhad, Mahvash
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p. 538 - 546
(2014/03/21)
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- Experimental and computational study of 6- Exo and 7- Endo cyclization of aryl radicals followed by Tandem SRN1 Substitution
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The reaction of N-allyl-N-(2-halobenzyl)-acetamides and derivatives was investigated in liquid ammonia under irradiation with the nucleophiles Me 3Sn-, Ph2P- and O 2NCH2-. Following this procedure, novel substituted 2-acetyl-1,2,3,4-tetrahydroisoquinolines and substituted 2-acetyl-2,3,4,5-tetrahydro-1H-benzo[c]azepines were obtained in good yields. These reactions are proposed to occur through the intermediacy of aryl radicals, which by intramolecular 6-exo or 7-endo attack to a double bond cyclize to give aliphatic radicals, which react along the propagation steps of the S RN1 chain cycle to afford the cyclic substituted compounds as main products. The reactions were modeled with DFT methods, which provide a rational understanding that relates the product distribution to the structure of the aliphatic radicals proposed as intermediates and the kinetic of their formation.
- Peisino, Lucas E.,Pierini, Adriana B.
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p. 4719 - 4729
(2013/07/11)
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- Aminopyridine- and Aminopyrimidinecarboxamides as CXCR2 Modulators
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There is disclosed aminopyridine-and aminopyrimidinecarboxamide compounds useful as pharmaceutical agents, synthesis processes, and pharmaceutical compositions which include aminopyridine- and aminopyrimidinecarboxamides compounds. More specifically, ther
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Page/Page column 14
(2012/03/10)
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- Reaction of InCl3 with various reducing agents: InCl 3-NaBH4-mediated reduction of aromatic and aliphatic nitriles to primary amines
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While alternative methods of preparing dichloroindium hydride (HInCl 2) via the in situ reduction of InCl3 using lithium amino borohydride (LAB) were explored, generation of HInCl2 from the reduction of InCl3 by sodium borohydride (NaBH4) was also re-evaluated for comparison. The reductive capability of the InCl 3/NaBH4 system was found to be highly dependent on the solvent used. Investigation by 11B NMR spectroscopic analyses indicated that the reaction of InCl3 with NaBH4 in THF generates HInCl2 along with borane-tetrahydrofuran (BH 3?THF) in situ. Nitriles underwent reduction to primary amines under optimized conditions at 25 °C using 1 equiv of anhydrous InCl 3 with 3 equiv of NaBH4 in THF. A variety of aromatic, heteroaromatic, and aliphatic nitriles were reduced to their corresponding primary amine in 70-99% isolated yields. Alkyl halide and nitrile functional groups were reduced in tandem by utilizing the reductive capabilities of both HInCl2 and BH3?THF in a one-pot reaction. Finally, the selective reduction of the carbon bromine bond in the presence of nitriles was achieved by generating HInCl2 via the reduction InCl3 with NaBH4 in CH3CN or with lithium dimethylaminoborohydride (MeLAB) in THF.
- Saavedra, Jaime Z.,Resendez, Angel,Rovira, Alexander,Eagon, Scott,Haddenham, Dustin,Singaram, Bakthan
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experimental part
p. 221 - 228
(2012/02/05)
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- Reductions of aliphatic and aromatic nitriles to primary amines with diisopropylaminoborane
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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.
- Haddenham, Dustin,Pasumansky, Lubov,DeSoto, Jamie,Eagon, Scott,Singaram, Bakthan
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supporting information; experimental part
p. 1964 - 1970
(2009/07/01)
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- Simple and efficient reduction of azides to amines using recyclable polymer-supported formate and zinc
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Polymer supported formate in conjunction with commercial zinc dust provides a mild and efficient procedure for the reduction of organic azides to corresponding amines. A variety of alkyl and aryl azides were selectively reduced in high yield and purity at room temperature.
- Prakasha, Kothathi C.,Sindhumol, Methatta,Ramesha Baba,Channe Gowda
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p. 284 - 286
(2008/02/08)
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- 2-aminobenzoxazole derivatives and combinatorial libraries thereof
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The present invention relates to novel 2-aminobenzoxazole derivative compounds of the following formula: wherein R1 to R4 and Z have the meanings provided herein. The invention further relates to combinatorial libraries containing two or more such compounds, as well as methods of preparing 2-aminobenzoxazole derivative compounds.
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- Aminoborohydrides. 12. Novel tandem SNAr amination-reduction reactions of 2-halobenzonitriles with lithium N,N-dialkylaminoborohydrides
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A novel tandem amination-reduction reaction has been developed in which 2-(N,N-dialkylamino)benzylamines are generated from 2-halobenzonitriles and lithium N,N-dialkylaminoborohydride (LAB) reagents. These reactions are believed to occur through a tandem SNAr amination-reduction mechanism wherein the LAB reagent promotes halide displacement by the N,N-dialkylamino group, and the nitrile is subsequently reduced. This one-pot procedure is complimentary to existing synthetic methods and is an attractive synthetic tool for the nucleophilic aromatic substitution of halobenzenes with less nucleophilic amines. The (N,N-dialkylamino)benzylamine products of this reaction are easily isolated after a simple aqueous workup procedure in very good to excellent yields.
- Thomas,Collins,Cuzens,Spiciarich,Goralski,Singaram
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p. 1999 - 2004
(2007/10/03)
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- Reductive coupling of aromatic oxims and azines to 1,2-diamines using Zn-MsOH or Zn-TiCl4
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The reduction of aromatic aldoxims and azines with Zn in the presence of MsOH or TiCl4 afforded N,N′-unsubstituted 1,2-diamines in one-step. The reductive coupling with Zn-MsOH gave meso 1,2-diamines selectively, whereas dl 1,2-diamines were fo
- Kise, Naoki,Ueda, Nasuo
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p. 2365 - 2368
(2007/10/03)
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- PALLADIUM ASSISTED ORGANIC REACTIONS. VII. THE PREPARATION OF CYCLOPALLADATED PRIMARY AND SECONDARY BENZYLAMINES
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A new method is described for the preparation of cyclopalladated benzylamines, involving the reaction of the ortho-bromobenzylamines with bis(dibenzylideneacetone)palladium(0).By using this method cyclopalladated complexes of simple primary and secondary benzylamines have been obtained for the first time.These complexes have been fully characterised as either the monomeric bromo(benzylamine-6-C,N)triphenylphosphinepalladium(II) derivatives or as the corresponding acetyl-acetonates. 1H and 13C NMR spectral data have been obtained and, in most cases, full assignments have been made.
- Clark, P. W.,Dyke, S. F.
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p. 389 - 396
(2007/10/02)
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