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Corresponding Imines (corresponding + imine)
Selected AbstractsWell-Defined Regioselective Iminopyridine Rhodium Catalysts for Anti-Markovnikov Addition of Aromatic Primary Amines to 1-OctyneADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 6 2009Carlos Alonso-Moreno Abstract A series of cationic rhodium(I) complexes of the type [Rh(N-N)(COD)][BPh4], containing the following iminopyridine-based bidentate nitrogen donor ligands (N-N): 2,6-diisopropyl- N -[1-(pyridin-2-yl)ethylidene]aniline (dipea, 1), 2,6-dimethyl- N -[1-(pyridin-2-yl)ethylidene]aniline (dmpea, 2), 2,4,6-trimethyl- N -[1-(pyridin-2-yl)ethylidene]aniline (tmpea, 3) and 2,6-diisopropyl- N -[1-(4-methylpyridin-2-yl)ethylidene]aniline] (dipmpea, 4), were synthesized and fully characterized. The intermolecular hydroamination of a terminal alkyne, such as 1-octyne, with primary aromatic amines in the presence of these cationic rhodium(I) catalysts occurred in an anti-Markovnikov fashion. The rhodium complexes catalyzed the regioselective formation of the E- isomer of the corresponding imine, without the formation of the Z -isomer or the Markovnikov product. These compounds are also presented as efficient regioselective catalysts for the hydroamination of anilines in the presence of air and/or water. [source] Synthesis of functionalized cyclic enamines from lithium alkylphenyl sulfones and N -carbo- tert -butoxy lactamsJOURNAL OF HETEROCYCLIC CHEMISTRY, Issue 1 2001Luis A. Arias Alkylphenyl sulfones 3 are appropriate synthons for the synthesis of 2-phenylsulfonyl alkylidene pyrro-lidine or piperidine derivatives 1 in good to moderate yields. The lithium alkyl sulfones 4 are first reacted with the desired protected lactams and then subjected to acidic methanolysis to afford the unusual enam-ines 1a-e. NMR studies (COSY 1H- 1H, COSY 1H- 13C, NOE) showed the Z enamines to exist in a dynamic equilibrium with the corresponding imines 2. The stereochemistry of the described compounds was confirmed by molecular calculations. [source] Nucleophilic and acid catalyst behavior of a protic ionic liquid in a molecular reaction media.JOURNAL OF PHYSICAL ORGANIC CHEMISTRY, Issue 5 2009Part Abstract This work presents a new approach using ionic liquids, namely ethylammonium nitrate. The aim was to analyze how the addition of small amounts of a protic ionic liquid to a pure molecular solvent, modifies the microscopic characteristics of a reaction medium. In order to achieve this, a kinetic study of nucleophilic aromatic substitution reactions between 1-fluoro-2,4-dinitrobenzene and 1-butylamine or piperidine was developed in this type of binary mixtures. We have detected nucleophiles competition originated by the presence of the ionic solvent at very low concentrations, observing the ethylamine derivative as the main substitution product. Moreover, in the light of previous results we have confirmed that the protic ionic liquid can act as both Brönsted acid and/or nucleophile. In this connection, we have selected the nucleophilic addition of amines to carbonyl compounds as reaction model. The protic ionic liquid in the presence of aromatic aldehydes substituted by electron-donating groups makes possible the formation of the corresponding imines with good yields. The results demonstrated that the influence of the protic ionic liquid is very important in the course of both reaction systems. Copyright © 2008 John Wiley & Sons, Ltd. [source] Ruthenium-catalyzed carbonylative cycloaddition reactions involving carbonyl and imino groups as assembling unitsTHE CHEMICAL RECORD, Issue 4 2008Naoto Chatani Abstract This paper describes carbonylative cycloaddition reactions catalyzed by Ru3(CO)12. Ru3(CO)12 was found to catalyze an intramolecular Pauson,Khand-type reaction. Carbonylative cycloaddition reactions involving a carbonyl group in aldehydes, ketones, and esters as a two-atom assembling unit were also achieved in the presence of Ru3(CO)12 as the catalyst. The reaction of 5-hexyn-1-al and 6-heptyn-1-al derivatives with CO in the presence of Ru3(CO)12 resulted in cyclocarbonylation from which bicyclic ,, ,-unsaturated lactones were obtained. Intermolecular [2,+,2,+,1] carbonylative cycloaddition of alkenes, ketones, and CO was also catalyzed by Ru3(CO)12 as the catalyst to give saturated ,-lactone derivatives. Simple ketones were not applicable, but ketones having a CO or CN group at the ,-position served as a good substrate. These reactions could be extended to carbonylative cycloaddition of the corresponding imines leading to ,-butyrolactam derivatives. The [4,+,1] carbonylative addition of ,,,-unsaturated imines leading to unsaturated ,-lactams was achieved with Ru3(CO)12. © 2008 The Japan Chemical Journal Forum and Wiley Periodicals, Inc. Chem Rec 8: 201,212; 2008: Published online in Wiley InterScience (www.interscience.wiley.com) DOI 10.1002/tcr.20149 [source] Magnetically Separable Gold Catalyst for the Aerobic Oxidation of AminesCHEMCATCHEM, Issue 1 2009Linda Aschwanden Abstract A magnetically separable, recyclable gold catalyst consisting of gold nanoparticles supported on intimately mixed superparamagnetic ceria/iron oxide has been prepared by simple addition of the preformed mixed oxide support and the gold precursor, Au(OAc)3, to the reaction mixture of the aerobic oxidation of amines. The catalyst was characterized by means of X-ray diffraction (XRD), N2 adsorption, superconducting quantum-interference device (SQUID) measurements, time-of-flight secondary ion mass spectrometry (TOF-SIMS), scanning transmission electron microscopy (STEM), and scanning electron microscopy with an energy-dispersive X-ray spectrometer (SEM-EDAX). Catalytic tests with various amines showed high selectivity to the corresponding imines (87,100,%), and good separation efficiency and recyclability of the catalyst. [source] Graphite-Supported Gold Nanoparticles as Efficient Catalyst for Aerobic Oxidation of Benzylic Amines to Imines and N -Substituted 1,2,3,4-Tetrahydroisoquinolines to Amides: Synthetic Applications and Mechanistic StudyCHEMISTRY - AN ASIAN JOURNAL, Issue 10 2009Man-Ho So Abstract Selective oxidation of amines using oxygen as terminal oxidant is an important area in green chemistry. In this work, we describe the use of graphite-supported gold nanoparticles (AuNPs/C) to catalyze aerobic oxidation of cyclic and acyclic benzylic amines to the corresponding imines with moderate-to-excellent substrate conversions (43,100,%) and product yields (66,99,%) (19,examples). Oxidation of N -substituted 1,2,3,4-tetrahydroisoquinolines in the presence of aqueous NaHCO3 solution gave the corresponding amides in good yields (83,93,%) with high selectivity (up to amide/enamide=93:4) (6,examples). The same protocol can be applied to the synthesis of benzimidazoles from the reaction of o -phenylenediamines with benzaldehydes under aerobic conditions (8,examples). By simple centrifugation, AuNPs/C can be recovered and reused for ten consecutive runs for the oxidation of dibenzylamine to N -benzylidene(phenyl)methanamine without significant loss of catalytic activity and selectivity. This protocol "AuNPs/C+O2" can be scaled to the gram scale, and 8.9,g (84,% isolated yield) of 3,4-dihydroisoquinoline can be obtained from the oxidation of 10,g 1,2,3,4-tetrahydroisoquinoline in a one-pot reaction. Based on the results of kinetic studies, radical traps experiment, and Hammett plot, a mechanism involving the hydrogen-transfer reaction from amine to metal and oxidation of M-H is proposed. [source] | |||||||||||||||||||