57535-59-8Relevant academic research and scientific papers
Switchable activity of a Ru catalyst bearing an annulated mesoionic carbene ligand for oxidation of primary amines
Bera, Jitendra K.,Din Reshi, Noor U,Pal, Nilay Kumar,Pal, Saikat,Pal, Sourav,Yadav, Suman
, (2022/01/31)
The catalytic activity of a Ru complex 1, bearing a fused π-conjugated imidazo[1,2–a][1,8]naphthyridine-based mesoionic carbene (MIC) ligand, is examined for the oxidation of primary amines. Complex 1 affords nitrile or imine depending on the nature of th
General and selective synthesis of primary amines using Ni-based homogeneous catalysts
Beller, Matthias,Chandrashekhar, Vishwas G.,Jagadeesh, Rajenahally V.,Jiao, Haijun,Murugesan, Kathiravan,Wei, Zhihong
, p. 4332 - 4339 (2020/05/18)
The development of base metal catalysts for industrially relevant amination and hydrogenation reactions by applying abundant and atom economical reagents continues to be important for the cost-effective and sustainable synthesis of amines which represent highly essential chemicals. In particular, the synthesis of primary amines is of central importance because these compounds serve as key precursors and central intermediates to produce value-added fine and bulk chemicals as well as pharmaceuticals, agrochemicals and materials. Here we report a Ni-triphos complex as the first Ni-based homogeneous catalyst for both reductive amination of carbonyl compounds with ammonia and hydrogenation of nitroarenes to prepare all kinds of primary amines. Remarkably, this Ni-complex enabled the synthesis of functionalized and structurally diverse benzylic, heterocyclic and aliphatic linear and branched primary amines as well as aromatic primary amines starting from inexpensive and easily accessible carbonyl compounds (aldehydes and ketones) and nitroarenes using ammonia and molecular hydrogen. This Ni-catalyzed reductive amination methodology has been applied for the amination of more complex pharmaceuticals and steroid derivatives. Detailed DFT computations have been performed for the Ni-triphos based reductive amination reaction, and they revealed that the overall reaction has an inner-sphere mechanism with H2metathesis as the rate-determining step.
Selective Acceptorless Dehydrogenation of Primary Amines to Imines by Core–Shell Cobalt Nanoparticles
Cui, Xinjiang,Li, Wu,Junge, Kathrin,Fei, Zhaofu,Beller, Matthias,Dyson, Paul J.
supporting information, p. 7501 - 7507 (2020/03/16)
Core–shell nanocatalysts are attractive due to their versatility and stability. Here, we describe cobalt nanoparticles encapsulated within graphitic shells prepared via the pyrolysis of a cationic poly-ionic liquid (PIL) with a cobalt(II) chloride anion. The resulting material has a core–shell structure that displays excellent activity and selectivity in the self-dehydrogenation and hetero-dehydrogenation of primary amines to their corresponding imines. Furthermore, the catalyst exhibits excellent activity in the synthesis of secondary imines from substrates with various reducible functional groups (C=C, C≡C and C≡N) and amino acid derivatives.
Easy Ruthenium-Catalysed Oxidation of Primary Amines to Nitriles under Oxidant-Free Conditions
Achard, Thierry,Egly, Julien,Sigrist, Michel,Maisse-Fran?ois, Aline,Bellemin-Laponnaz, Stéphane
supporting information, p. 13271 - 13274 (2019/10/21)
A dehydrogenation of primary amine to give the corresponding nitrile under oxidant- and base-free conditions catalysed by simple [Ru(p-cym)Cl2]2 with no extra ligand is reported. The system is highly selective for alkyl amines, whereas benzylamine derivatives gave the nitrile product together with the imine in a ratio ranging from 14:1 to 4:1 depending on the substrate. Preliminary mechanistic investigations have been performed to identify the key factors that govern the selectivity.
Ligand controlled switchable selectivity in ruthenium catalyzed aerobic oxidation of primary amines
Ray, Ritwika,Chandra, Shubhadeep,Yadav, Vishal,Mondal, Prasenjit,Maiti, Debabrata,Lahiri, Goutam Kumar
supporting information, p. 4006 - 4009 (2017/04/11)
A ligand controlled catalytic system for the aerobic oxidation of 1° amines to nitriles and imines has been developed where the varying π-acidic feature of BIAN versus phen in the frameworks of ruthenium catalysts facilitates switchable selectivity.
Symbiotic Transition-Metal and Organocatalysis for Catalytic Ambient Amine Oxidation and Alkene Reduction Reactions
Murray, Alexander T.,King, Rose,Donnelly, Joseph V. G.,Dowley, Myles J. H.,Tuna, Floriana,Sells, Daniel,John, Matthew P.,Carbery, David R.
, p. 510 - 514 (2016/02/20)
A new oxidation reaction based on two simple catalysts, namely, alloxan and a CuI salt, is highly effective for the aerobic oxidation and oxidative cross-coupling of amines. The reaction is operationally simple, reaction atmospheres enriched in dioxygen are obviated, and neither catalyst component requires prior synthesis. Mechanistic investigations have been performed and point towards a complex reaction manifold with evidence that supports a catalytic cycle that does not proceed through a quinone-imine step. Additionally, this dual catalyst system is efficient to effect diimide-mediated hydrogenation reactions of alkenes and alkynes, a transformation that has not been reported previously in the context of quinone catalyst systems.
Selective oxidation of amines to aldehydes or imines using laccase-mediated bio-oxidation
Galletti, Paola,Funiciello, Federica,Soldati, Roberto,Giacomini, Daria
, p. 1840 - 1848 (2015/06/02)
An efficient and practical chemo-enzymatic aerobic oxidation in water of benzylamines to obtain aldehydes or imines is described. Laccase from Trametes versicolor was chosen as biocatalyst, and TEMPO (radical 2,2,6,6-tetramethylpiperidine 1-oxyl) as mediator. A study on the pH dependence of the aqueous medium allowed us to realise a fine tuning on product selectivity. Under our optimized reaction conditions, the bio-oxidation of a series of primary, secondary and cyclic amines has been achieved.
Efficacious N-protection of O-aryl sulfamates with 2,4-dimethoxybenzyl groups
Reuillon, Tristan,Bertoli, Annalisa,Griffin, Roger J.,Miller, Duncan C.,Golding, Bernard T.
, p. 7610 - 7617 (2012/10/29)
Sulfamates are important functional groups in certain areas of current medicinal chemistry and drug development. Alcohols and phenols are generally converted into the corresponding primary sulfamates (ROSO2NH 2 and ArOSO2NH2, respectively) by reaction with sulfamoyl chloride (H2NSO2Cl). The lability of the O-sulfamate group, especially to basic conditions, usually restricts this method to a later stage of a synthesis. To enable a more flexible approach to the synthesis of phenolic O-sulfamates, a protecting group strategy for sulfamates has been developed. Both sulfamate NH protons were replaced with either 4-methoxybenzyl or 2,4-dimethoxybenzyl. These N-protected sulfamates were stable to oxidising and reducing agents, as well as bases and nucleophiles, thus rendering such masked sulfamates suitable for multi-step synthesis. The protected sulfamates were synthesised by microwave heating of 1,1′-sulfonylbis(2-methyl-1H-imidazole) with a substituted phenol to give an aryl 2-methyl-1H-imidazole-1-sulfonate. This imidazole-sulfonate was N-methylated by reaction with trimethyloxonium tetrafluoroborate, which enabled subsequent displacement of 1,2-dimethylimidazole by a dibenzylamine (e.g. bis-2,4-dimethoxybenzylamine). The resulting N-diprotected, ring-substituted phenol O-sulfamates were further manipulated through reactions at the aryl substituent and finally deprotected with trifluoroacetic acid to afford a phenol O-sulfamate. The use of 2,4-dimethoxybenzyl was particularly attractive because deprotection occurred quantitatively within 2 h at room temperature with 10% trifluoroacetic acid in dichloromethane. The four key steps in the protocol described [reaction of 1,1′-sulfonylbis(2-methyl-1H-imidazole) with a phenol, methylation, displacement with a dibenzylamine and deprotection] all proceeded in very high yields.
Facile synthesis of 1-aryl-2,3-dihydro-1H-isoindoles by cyclization of N-formyliminium ion via geometrically disfavored 5-ENDO-trig process
Kitabatake, Michikazu,Saitoh, Toshiaki,Sano, Takehiro,Horiguchi, Yoshie
scheme or table, p. 1177 - 1181 (2009/11/30)
Synthesis of l-aryl-2,3-dihydro-1H-isoindoles (isoindolines) (10) was achieved in a highly effective manner via acid catalyzed cyclization of N-foimyliminium ion (8) obtained from 2,3-dimethoxybenzylamine and carbonyl compounds with acetic-formic anhydride under a one pot procedure. This Pictet-Spengler type reaction provides a convenient method for preparing 1-arylisoindolines.
Resistance-modifying agents. 11. Pyrimido[5,4-d]pyrimidine modulators of antitumor drug activity. Synthesis and structure-activity relationships for nucleoside transport inhibition and binding to α1-acid glycoprotein
Curtin, Nicola J.,Barlow, Hannah C.,Bowman, Karen J.,Calvert, A. Hilary,Davison, Richard,Golding, Bernard T.,Huang, Bing,Loughlin, Peter J.,Newell, David R.,Smith, Peter G.,Griffin, Roger J.
, p. 4905 - 4922 (2007/10/03)
The cardiovascular and antithrombotic agent dipyridamole (DP) has potential therapeutic utility as a modulator of the activity of antimetabolite antitumor agents by virtue of its inhibition of nucleoside transport. However, the activity of DP can be compromised by binding to the acute phase serum protein, α1-acid glycoprotein (AGP). Analogues of DP were synthesized and evaluated as inhibitors of 3H-thymidine uptake into L1210 leukamia cells in the presence and absence of 5 mg/mL AGP. Compounds with potency similar to that of DP were identified where the piperidino substituents at the 4,8-positions were replaced by 4?-methoxybenzylamino, 3?,4?-dimethoxybenzylamino, or piperonylamino groups. Replacement of the diethanolamino groups at the 2,6-positions of DP by alkylamino or alkoxy substituents was tolerated, although at least one oxygen-bearing function (hydroxyl or alkoxy) was required in the side chain for activity comparable to that of DP. Whereas AGP completely ablated the activity of DP, the majority of the newer compounds synthesized retained significant activity in the presence of excess AGP, although replacement of the piperidino groups at the 4,8-positions by N-methylbenzylamino substituents did, in some cases, restore susceptibility to AGP. Selected compounds have been demonstrated to prevent rescue from antifolate cytotoxicity, mediated by nucleoside salvage.
