4439-54-7Relevant academic research and scientific papers
Efficient One-Pot Reductive Aminations of Carbonyl Compounds with Aquivion-Fe as a Recyclable Catalyst and Sodium Borohydride
Airoldi, Veronica,Piccolo, Oreste,Roda, Gabriella,Appiani, Rebecca,Bavo, Francesco,Tassini, Riccardo,Paganelli, Stefano,Arnoldi, Sebastiano,Pallavicini, Marco,Bolchi, Cristiano
supporting information, p. 162 - 168 (2019/12/11)
A one-pot reductive amination of aldehydes and ketones with NaBH4 was developed with a view to providing efficient, economical and greener synthetic conditions. A recyclable iron-based Lewis catalyst, Aquivion-Fe, was used to promote imine formation in cyclopentyl methyl ether, followed by the addition of a small amount of methanol to the reaction mixture to enable C=N reduction by NaBH4. The protocol, applied to a wide number of amines and carbonyl compounds, resulted in ever complete conversion of these latter with excellent chemoselectivity towards the expected amination products in the most cases. Isolated yields, determined for a selection of the screened substrates, were found consistent with the previously obtained conversion and selectivity data. Cinacalcet, an important active pharmaceutical ingredient, was efficiently prepared by the title procedure.
Synthesis and Cytotoxicity of Octahydroepoxyisoindole-7-carboxylic Acids and Norcantharidin–Amide Hybrids as Norcantharidin Analogues
Hizartzidis, Lacey,Gilbert, Jayne,Gordon, Christopher P.,Sakoff, Jennette A.,McCluskey, Adam
, p. 1152 - 1161 (2019/05/24)
Octahydroepoxyisoindole analogues of norcantharidin were accessed through a Diels–Alder reaction of an amine-substituted furan with maleic anhydride and subsequent reduction of the bicyclo[2.2.1]heptene olefin. Despite retention of the carboxylate and the ether bridgehead known to impart cytotoxic activity to norcantharidin, none of these analogues displayed notable cytotoxicity against the 11 cell lines examined: HT29 (colon), MCF-7 (breast), A2780 (ovarian), H460 (lung), A431 (skin), Du145 (prostate), BE2-C (neuroblastoma), SJ-G2 and U87 (glioblastoma), MIA (pancreatic), and SMA (spontaneous murine astrocytoma). The incorporation of an amino-substituted system post-synthesis of norcantharidin afforded facile access to 14 acid/amide-substituted norcantharidin analogues. Of these, only four displayed sufficient activity at the initial 25 μm compound screening dose to warrant full evaluation of growth inhibition. Common to these analogues was the presence of a 4-biphenyl moiety, and in particular 3-(2-(furan-2-ylmethyl)-3-(4-biphenylamino)-3-oxopropylcarbamoyl)-7-oxabicyclo[2.2.1]heptane-2-carboxylic acid (13 c) and 3-(2-(pyrrole-2-ylmethyl)-3-(4-biphenylamino)-3-oxopropylcarbamoyl)-7-oxabicyclo[2.2.1]heptane-2-carboxylic acid (24) displayed high levels of cytotoxicity, returning GI50 values of 15 nm (HT29) to 2.9 μm (U87) and 17 nm (SMA) to 2.8 μm (U87), respectively. These are the most cytotoxic norcantharidin analogues reported to date.
Recyclable cobalt(0) nanoparticle catalysts for hydrogenations
Büschelberger, Philipp,Reyes-Rodriguez, Efrain,Sch?ttle, Christian,Treptow, Jens,Feldmann, Claus,Jacobi Von Wangelin, Axel,Wolf, Robert
, p. 2648 - 2653 (2018/05/30)
The search for new hydrogenation catalysts that replace noble metals is largely driven by sustainability concerns and the distinct mechanistic features of 3d transition metals. Several combinations of cobalt precursors and specific ligands in the presence of reductants or under high-thermal conditions were reported to provide active hydrogenation catalysts. This study reports a new method of preparation of small, monodisperse Co(0) nanoparticles (3-4 nm) from the reduction of commercial CoCl2 in the absence of ligands or surfactants. High catalytic activity was observed in hydrogenations of alkenes, alkynes, imines, and heteroarenes (2-20 bar H2). The magnetic properties enabled catalyst separation and multiple recyclings.
Synthesis of Symmetric and Unsymmetric Secondary Amines from the Ligand-Promoted Ruthenium-Catalyzed Deaminative Coupling Reaction of Primary Amines
Arachchige, Pandula T. Kirinde,Lee, Hanbin,Yi, Chae S.
, p. 4932 - 4947 (2018/05/08)
The catalytic system generated in situ from the tetranuclear Ru-H complex with a catechol ligand (1/L1) was found to be effective for the direct deaminative coupling of two primary amines to form secondary amines. The catalyst 1/L1 was highly chemoselective for promoting the coupling of two different primary amines to afford unsymmetric secondary amines. The analogous coupling of aniline with primary amines formed aryl-substituted secondary amines. The treatment of aniline-d7 with 4-methoxybenzylamine led to the coupling product with significant deuterium incorporation on CH2 (18% D). The most pronounced carbon isotope effect was observed on the α-carbon of the product isolated from the coupling reaction of 4-methoxybenzylamine (C(1) = 1.015(2)). A Hammett plot was constructed from measuring the rates of the coupling reaction of 4-methoxyaniline with a series of para-substituted benzylamines 4-X-C6H4CH2NH2 (X = OMe, Me, H, F, CF3) (ρ = -0.79 ± 0.1). A plausible mechanistic scheme has been proposed for the coupling reaction on the basis of these results. The catalytic coupling method provides an operationally simple and chemoselective synthesis of secondary amine products without using any reactive reagents or forming wasteful byproducts.
Copper-Catalyzed Alkylation of Aliphatic Amines Induced by Visible Light
Matier, Carson D.,Schwaben, Jonas,Peters, Jonas C.,Fu, Gregory C.
supporting information, p. 17707 - 17710 (2017/12/26)
Although the alkylation of an amine by an alkyl halide serves as a textbook example of a nucleophilic substitution reaction, the selective mono-alkylation of aliphatic amines by unactivated, hindered halides persists as a largely unsolved challenge in organic synthesis. We report herein that primary aliphatic amines can be cleanly mono-alkylated by unactivated secondary alkyl iodides in the presence of visible light and a copper catalyst. The method operates under mild conditions (-10 °C), displays good functional-group compatibility, and employs commercially available catalyst components. A trapping experiment with TEMPO is consistent with C-N bond formation via an alkyl radical in an out-of-cage process.
Selective hydrogenation of nitriles to secondary amines catalyzed by a pyridyl-functionalized and alkenyl-tethered NHC-Ru(II) complex
Saha, Sayantani,Kaur, Mandeep,Singh, Kuldeep,Bera, Jitendra K.
, p. 87 - 94 (2016/06/09)
A set of Co(III) and Ru(II) compounds are synthesized bearing pyridyl-functionalized and alkenyl-tethered N-heterocyclic carbene (NHC) ligand (L1). [CoIII(L1)3](PF6)3 (1) was synthesized by the reaction of [L1H]PF6, Co(OAc)2.4H2O, K2CO3 in tetrahydrofuran (THF) under refluxing condition. [RuIIL1(η6-p-cymene)Cl]PF6 (2) was synthesized via transmetallation method. For both compounds, the NHC ligand chelates the metal through carbene carbon and pyridyl nitrogen whereas the butenyl unit remains free. Compound 2 hydrogenates organic nitriles efficiently providing selectively secondary amines. In the presence of external amines, unsymmetrical secondary amines are also obtained.
Ruthenium-catalyzed N-alkylation of amines with alcohols under mild conditions using the borrowing hydrogen methodology
Enyong, Arrey B.,Moasser, Bahram
, p. 7553 - 7563 (2014/09/17)
Using a simple amino amide ligand, ruthenium-catalyzed one-pot alkylation of primary and secondary amines with simple alcohols was carried out under a wide range of conditions. Using the alcohol as solvent, alkylation was achieved under mild conditions, even as low as room temperature. Reactions occurred with high conversion and selectivity in many cases. Reactions can also be carried out at high temperatures in organic solvent with high selectivity using stoichiometric amounts of the alcohol.
Aryne cycloaddition with 3-oxidopyridinium species
Ren, Hailong,Wu, Chunrui,Ding, Xiuxiu,Chen, Xiaoge,Shi, Feng
supporting information, p. 8975 - 8984,10 (2012/12/12)
The [3 + 2] cycloaddition of arynes with 3-oxidopyridinium species is examined using the Kobayashi benzyne precursor. The reaction affords a bicyclo[3.2.1] skeleton under mild conditions. A [7 + 2] cycloaddition mode with a subsequent pyridine ring-opening event has also been observed.
Preparative synthesis of 7-carboxy-2-R-isoindol-1-ones
Varlamov,Boltukhina,Zubkov,Sidorenko,Chernyshev,Grudinin
, p. 22 - 28 (2007/10/03)
A preparative method for the synthesis of 7-carboxy-2-R-isoindol-1-ones was developed on the basis of the [4+2] cycloaddition of secondary furfurylamines to maleic anhydride.
Intra-molecular Diels-Alder reactions of citraconamic acids from furfurylamines and citraconic anhydride: Effects of substitution in the furan ring on regioselectivity
Murali, Rajappa,Surya Prakash Rao,Scheeren, Hans W
, p. 3165 - 3174 (2007/10/03)
Regioselectivity in the intra-molecular Diels-Alder (IMDA) reaction of furfurylcitraconamic acids derived from N-benzylfurfurylamines and citraconic anhydride can be controlled by substituents located in the furan ring and by reaction conditions. Reactions conducted under kinetic conditions resulted in cycloaddition products having methyl and aminomethylene substituent in 1,3-relationship whereas under thermodynamic conditions, excepting in the case of the 3-methylsulfanyl group, the products rearranged to more stable cycloadducts in which the substituents are in 1,2-relationship. Product formation can be explained on the basis of frontier orbital interactions and steric considerations.
