- Stereoselective synthesis of α-alkylidene β-oxo amides by palladium-catalyzed carbonylation
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A direct method to obtain α-alkylidene β-oxo amides by the palladium-catalyzed carbonylation of α-chloro ketones in the presence of aromatic imines has been described. The methodology can be applied to a variety of C-aryl imines bearing N-aryl or N-alkyl substituents. The entire process is highly stereoselective and affords the α-alkylidene β-oxo amides only as (Z) isomers. A mechanistic hypothesis involving an acyl-β-lactam intermediate has also been proposed.
- Perrone, Serena,Salomone, Antonio,Caroli, Antonio,Falcicchio, Aurelia,Citti, Cinzia,Cannazza, Giuseppe,Troisi, Luigino
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- Reductive amination of furfural over Me/SiO2-SO3H (Me: Pt, Ir, Au) catalysts
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Gold, platinum and iridium colloids were supported on sulfonic acid-functionalized silica and were employed for the reductive amination of furfural. The catalysts were characterized by N2-physisorption at 77 K, X-ray diffraction, H2
- Martínez, José J.,Nope, Eliana,Rojas, Hugo,Brijaldo, María H.,Passos, Fabio,Romanelli, Gustavo
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Read Online
- Nickel Complexes Bearing N,N,O-Tridentate Salicylaldiminato Ligand: Efficient Catalysts for Imines Formation via Dehydrogenative Coupling of Primary Alcohols with Amines
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Treatment of salicylaldiminato ligand L1H-L2H (L1H = 2,4-di-tert-butyl-6-((quinolin-8-ylimino)methyl)phenol; L2H = 2,4-di-tert-butyl-6-(((2-(diethylamino)ethyl)imino)methyl)phenol) with Ni(OAc)2·4H2O in refluxing ethanol afforded nickel complexes [(L1)Ni(OAc)] (1) and [(L2)Ni(OAc)] (2), respectively. Reaction of L3H (L3H = (2,4-di-tert-butyl-6-(((2-(pyridin-2-yl)ethyl)imino)methyl)phenol)) with Ni(OAc)2·4H2O in the presence of excess triethylanmine gave the dual ligands coordinated nickel complex [(L2)2Ni] (3). Complexes 1-3 were well characterized by high-resolution mass spectrometry, infrared spectroscopy, elemental analysis, and X-ray diffraction analysis. All the three Ni(II) complexes exhibited efficient activity and good selectivity in the acceptorless dehydrogenative coupling of alcohols and amines to produce imines and diimines. The present protocol provides an atom-economical and sustainable route for the synthesis of various imine derivatives by employing an earth-abundant nickel salt and easily prepared salicylaldiminato ligands.
- Han, Zhangang,Hao, Zhiqiang,Lin, Jin,Lu, Guo-Liang,Zhang, Junhua,Zhang, Xiaoying
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p. 3843 - 3853
(2021/11/18)
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- A Highly Selective Manganese-Catalyzed Synthesis of Imines under Phosphine-Free Conditions
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An efficient and highly selective phosphine-free NN-manganese(I) complex catalyst system was developed for the acceptorless dehydrogenative coupling of alcohols with amines to form imines. The coupling reactions underwent at 3 mol % catalyst loading, and a large range of alcohols and amines with diverse functional groups was applied, including challenging diol and diamine. The target imine products were obtained in good to excellent yields. The present work provides an alternative method to construct highly active nonprecious metal complex catalysts based on phosphine-free ligands.
- Chai, Huining,Yu, Kun,Liu, Bo,Tan, Weiqiang,Zhang, Guangyao
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p. 217 - 226
(2020/01/31)
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- Ruthenium-Catalyzed C-H Arylation and Alkenylation of Furfural Imines with Boronates
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A Ru0-catalyzed direct C-H arylation and alkenylation of furfural imines with aryl- or alkenyl-boronates, in the presence of benzylideneacetone as a sacrificial hydride acceptor, is disclosed. This reaction provides access, after hydrolysis, to C3-arylated or vinylated furfural derivatives, and thus valorizes these relevant building-blocks obtained from lignocellulosic biomass. This approach, involving C-H activation by a Ru0/RuII, cycle offers several advantages, notably simple, mild and neutral reaction conditions.
- Siopa, Filipa,Ramis Cladera, Valérie-Anne,Afonso, Carlos Alberto Mateus,Oble, Julie,Poli, Giovanni
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supporting information
p. 6101 - 6106
(2018/09/18)
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- Singleton inhibitors of sumoylation enzymes and methods for their use
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According to the embodiments described herein, a SUMOylation inhibitor compound comprising a singleton scaffold is provided. In some embodiments, a method for inhibiting a SUMOylation enzyme in a cell is provided. Such a method may include administering a
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Page/Page column 30
(2016/02/09)
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- Synthesis of cucurbitine derivatives: facile straightforward approach to methyl 3-amino-4-aryl-1-methylpyrrolydine-3-carboxylates
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A general three- or four-step synthesis of cis- and trans-substituted cucurbitine (3-aminopyrrolidine-3-carboxylic acid) derivatives from methyl 2-nitroacetate is reported. The first step utilizes a Knoevenagel condensation with five different aromatic imines or their corresponding aldehydes to form (Z/E)-mixtures of α-nitro acrylates. The second step gives rise to the pyrrolidine-core structures of the title compounds by a 1,3-dipolar cycloaddition reaction using an azomethine ylide. The last step consists of reduction of the nitro group to yield both diastereoisomers of the corresponding 4-aryl cucurbitine methyl esters.
- Blanco-Ania, Daniel,Hermkens, Pedro H.H.,Sliedregt, Leo A.J.M.,Scheeren, Hans W.,Rutjes, Floris P.J.T.
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supporting information; experimental part
p. 5393 - 5401
(2009/10/17)
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- Antifungal and cytotoxic activities of some N-substituted aniline derivatives bearing a hetaryl fragment
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Diverse N-substituted anilines bearing hetaryl fragments were easily prepared from corresponding aldimines derived from commercially available aromatic aldehydes and anilines. 2-Furyl substituted anilines showed very good antifungal activities against dermatophytes, particularly against Trichophyton rubrum (MIC = 3.12-6.25 μg/mL). In addition, all active compounds, 45-47, 73, and 74, were tested for cytotoxic activities against breast (MCF-7), lung (H-460), and central nervous system (SF-268) human cancer cell lines with the NCI-anticancer-drug screen. The activity of amines described in this paper, along with the low toxicity of most of them, shows promise for the future development of non-toxic new antimycotic agents.
- Kouznetsov, Vladímir V.,Vargas Méndez, Leonor Y.,Sortino, Maximiliano,Vásquez, Yelkaira,Gupta, Mahabir P.,Freile, Mónica,Enriz, Ricardo D.,Zacchino, Susana A.
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p. 794 - 809
(2008/09/17)
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- Oxidation of secondary amines catalyzed by dirhodium caprolactamate
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The dirhodium caprolactamate [Rh2(cap)4] catalyzed oxidation of secondary amines to imines by tert-butyl hydroperoxide (TBHP) occurs with high chemo- and regioselectivity. The Royal Society of Chemistry.
- Choi, Hojae,Doyle, Michael P.
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p. 745 - 747
(2007/10/03)
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- Synthetic and mechanistic studies of indium-mediated allylation of imines in ionic liquids
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(Chemical Equation Presented) Aldimines derived from aryl and non-enolizable aliphatic aldehydes were allylated with allyl bromide mediated by indium powder in [bpy][BF4] (bpy = N-butylpyridine) to give good yields of the corresponding homoallylic amines. Selective formation of monoallylated amines can be achieved by varying the amount of bromide ion additive in the form of [bpy][Br]. The transient organoindium intermediates, allylindium-(I) and allylindium(III) dibromide formed in the reaction, were studied by NMR spectroscopy to explain the selectivity.
- Man, Chun Law,Tin, Wai Cheung,Wong, Kwok-Yin,Tak, Hang Chan
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p. 923 - 929
(2007/10/03)
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- An efficient synthesis of isoindolo[2,1-a]quinoline derivatives via imino Diels-Alder and intramolecular Diels-Alder reactions with furan
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The straightforward synthesis of new isoindolo[2,1-a]quinoline derivatives from 2,4-disubstituted 1,2,3,4-tetrahydroquinolines bearing a furan fragment via the intramolecular Diels-Alder reaction is reported. The synthesis of key precursors was realized w
- Kouznetsov, Vladimir V.,Cruz, Uriel Mora,Zubkov, Fedor I.,Nikitina, Eugenia V.
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p. 375 - 384
(2008/01/06)
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- One-pot synthesis of N-chloroacetyl 1-aminoalkyl phosphonates - Precursors of 4-phosphono-β-lactams
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4-Phosphono-β-lactams are synthesized via a three-step sequence, including final formation of the C3-C4 bond through a phosphorus-stabilized carbanion. The chlorinated precursors can be synthesized via two different methods: a one-pot N-acylation of an aromatic imine followed by addition of a trialkyl phosphite or phosphonylation of a suitable imine followed by N-acylation in a separate reaction step. The former method was preferred because of the ease of the reaction and the good yields obtained. Georg Thieme Verlag Stuttgart.
- Moonen, Kristof,Stevens, Christian V.
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p. 3603 - 3612
(2007/10/03)
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- Synthesis of 4-phosphono-β-lactams via phosphite addition to acyliminium salts
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4-Aryl-4-phosphono-β-lactams are prepared by acylation of iminium salts with chloroacetyl chloride followed by phosphite addition and ring closure using sodium hydride as a base. Deacylation of the iminium salt is in competition with the desired addition of phosphites to acyliminium salts, which lowers the yield of the reaction.
- Stevens, Christian V.,Vekemans, Wannes,Moonen, Kristof,Rammeloo, Thomas
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p. 1619 - 1622
(2007/10/03)
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- Molecular structure of di-aryl-aldimines by multinuclear magnetic resonance and X-ray diffraction
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The complete 1H, 13C and 15N NMR analyses for a series of 25 diaryl-aldimines containing phenyl, pyridyl, pyrazolone and furanyl moieties are described herein. Detailed evaluation of substituent chemical shift and coupling constant effects showed that interaction between the lone pair of the pyrazolone carbonyl group or the nitrogen of 2-substitued pyridines with the aldimine hydrogen increases the 1JCH value and shifts the resonance signal for this hydrogen to high frequency, in the 1H NMR spectra. The X-ray crystal structure analysis of pyrazolone substituted aldimines evidenced the planarity of the aryl groups which are conjugated with the C=N double bond. In the case of the N-(2-pyridinemethylene)-1,5-dimethyl-2-phenyl-1,2-dihydro-pyrazol-3-one, two rotamers were observed in the same unit cell.
- Montalvo-González, Rubén,Ariza-Castolo, Armando
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p. 375 - 389
(2007/10/03)
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- Catalytic, Three-Component Assembly Reaction for the Synthesis of Pyrrolidines
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Equation presented. Copper(I) salts catalyze the three-component assembly reaction between an α-diazo ester, an imine, and various alkenes and alkynes to form substituted pyrrolidines with excellent to good diastereoselectivities in high yields. The transition metal-catalyzed decomposition of the α-diazo compound in the presence of the imine likely generates a transient azomethine ylid that undergoes addition with various dipolarophiles in a highly convergent manner.
- Galliford, Chris V.,Beenen, Melissa A.,Nguyen, Sonbinh T.,Scheidt, Karl A.
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p. 3487 - 3490
(2007/10/03)
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- Oxidation of various secondary amines to imines with N-tert-butylphenylsulfinimidoyl chloride
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Various secondary amines were smoothly oxidized to the corresponding imines at -78 °C by using N-tert-butylphenylsulfinimidoyl chloride and DBU.
- Mukaiyama, Teruaki,Kawana, Asahi,Fukuda, Yoshio,Matsuo, Jun-Ichi
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p. 390 - 391
(2007/10/03)
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- Some furfural derivatives as nitrification inhibitors
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Three series of furfural derivatives, namely N-O-furfural oxime ethers, furfural Schiff bases (furfurylidene anilines), and furfural chalcones, have been synthesized and evaluated for nitrification inhibition activity in laboratory incubation studies in typic Ustocrept soil. Furfural oxime ethers and furfural Schiff bases showed potential activity, but furfural chalcones were only mildly active. N-O-ethyl furfural oxime among the oxime ethers, and furfurylidine-4-chloroaniline among the furfural Schiff bases, performed the best. These two compounds showed more than 50% nitrification inhibition on the 45th day at 5% dose as compared to 73% inhibition by nitrapyrin. Activity of furfural oxime ethers decreased with an increase in carbon atoms in the N-O-alkyl side chain. Introduction of a chlorine atom in the phenyl ring of furfurylidene anilines increased the persistence of their activity. N-O-Ethyl furfural oxime and furfurylidine-4-chloroaniline coated urea performed at par with their application in solution form. Ethyl and N-O-isopropyl oxime, as well as chloro- and nitro-substituted Schiff bases, did not reveal any phytotoxicity (adverse effect on germination) on chickpea seeds (Cicer arietinum) even at the highest dose (40 ppm, soil basis).
- Datta,Walia,Parmar
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p. 4726 - 4731
(2007/10/03)
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