50967-59-4Relevant academic research and scientific papers
β-Enaminone Synthesis from 1,3-Dicarbonyl Compounds and Aliphatic and Aromatic Amines Catalyzed by Iron Complexes of Fused Bicyclic Imidazo[1,5-a]pyridine Derived N-Heterocyclic Carbenes
Prakasham,Gangwar, Manoj Kumar,Ghosh, Prasenjit
, p. 295 - 313 (2019/01/24)
A series of Fe–NHC complexes (1–2)c of the fused bicyclic imidazo[1,5-a]pyridine framework of the type [CpFe(2-R-imidazo[1,5-a]pyridin-3-ylidene)(CO)2]BF4 {R = mesityl (1c), nPr (2c)} successfully carried out the synthesis of β-enamino ketones (3–10) and (17–27) and β-enamino esters (11–16) and (28–36) by the condensation of acyclic and cyclic 1,3-dicarbonyl compounds and various aliphatic and aromatic amines in the presence of light irradiation. Quite significantly, the catalytically relevant substrate adduct species of the type [CpFe(NHC)(acac)] (2e) and the product adduct species of the type [CpFe(NHC)(β-enaminone)] (2f) of the Fe–NHC precatalyst (2c) have been detected by mass spectrometry study. The [CpFe(2-R-imidazo[1,5-a]pyridin-3-ylidene)(CO)2]BF4 {R = mesityl (1c), nPr (2c)} complexes were obtained from their respective N–heterocyclic carbene precursors namely, the 2-R-imidazo[1,5-a]pyridin-2-ium chloride {R = mesityl (1a), nPr (2a)} by the reaction with CpFe(CO)2I in the presence of KN(SiMe3)2 followed by the salt metathesis reaction with AgBF4.
Bimetallic Ag-Cu alloy nanoparticles as a highly active catalyst for the enamination of 1,3-dicarbonyl compounds
Rout, Lipeeka,Kumar, Aniket,Dhaka, Rajendra S.,Dash, Priyabrat
, p. 49923 - 49940 (2016/06/15)
Bimetallic nanoparticles, particularly those based on copper, have recently attracted a great deal of attention for the development of low cost and highly active catalysts due to the synergistic interaction between individual metal components. In this work, bimetallic Ag-Cu alloy nanoparticles were explored as a highly active and reusable catalyst for the enamination of 1,3-dicarbonyls using diverse amines. The nanocatalysts were intensively characterized by ultraviolet-visible (UV-Vis) spectroscopy, X-ray diffraction (XRD), high-resolution transmission electron microscopy-energy-dispersive spectroscopy (HRTEM-EDS) and valence band and core level X-ray photoelectron spectroscopy (XPS) to study the effect of the bimetallic structure and composition. In comparison to monometallic Ag and Cu nanoparticles, the alloyed Ag-Cu nanoparticles showed a high catalytic performance and the resultant catalytic activity was dependant on the Ag to Cu ratio. This enhanced catalytic activity should be related to the electronic interaction between Ag and Cu nanoparticles formed due to the intimate contact between them. Our study may serve as a foundation for designing efficient alloyed nanocatalysts for fine chemical synthesis via enamination reactions.
Design of a graphene oxide-SnO2 nanocomposite with superior catalytic efficiency for the synthesis of β-enaminones and β-enaminoesters
Kumar, Aniket,Rout, Lipeeka,Dhaka, Rajendra S.,Samal, Saroj L.,Dash, Priyabrat
, p. 39193 - 39204 (2015/05/20)
A graphene oxide (GO)-SnO2-based nanocomposite was synthesized by decorating the graphene oxide surface with SnO2 nanoparticles via a solvothermal process. The nanocomposite was characterized using Fourier transform infrared spectra (FTIR), FT-Raman spectroscopy, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Field-emission Scanning electron microscopy (FE-SEM), Energy dispersive X-ray spectroscopy (EDS), Transmission electron microscopy (TEM) and N2 adsorption/desorption study. The FE-SEM and TEM images demonstrate the uniform distribution of the SnO2 nanoparticles on the GO surface and high-resolution transmission electron microscopy (HRTEM) confirms an average particle size of 8-12 nm. The GO-SnO2 nanocomposite has been found to be an extremely efficient catalyst for the synthesis of β-enaminones and β-enaminoesters in methanol solvent and also, in solventless conditions. The GO-SnO2 nanocomposites exhibited synergistically more superior catalytic efficiency compared to pure graphene oxide and SnO2 nanoparticles. The reaction conditions were optimized by changing different parameters such as catalyst, solvent, catalyst loading, and temperature. It has been found that the catalyst gave higher activity under solventless conditions than methanol. The GO-SnO2 composite was recycled for up to four cycles with minimal loss in activity.
Gold(III) N-heterocyclic carbene complexes mediated synthesis of β-enaminones from 1,3-dicarbonyl compounds and aliphatic amines
Samantaray, Manoja K.,Dash, Chandrakanta,Shaikh, Mobin M.,Pang, Keliang,Butcher, Ray J.,Ghosh, Prasenjit
experimental part, p. 1840 - 1848 (2011/04/23)
A series of gold(III) N-heterocyclic carbene complexes [1-(R 1)-3-(R2)imidazol-2-ylidene]AuBr3 [R 1 = i-Pr, R2 = CH2Ph (1c); R1 = mesityl, R2 = CH2Ph (2c);
Efficient synthesis of alkyl β-diketimines
Bradley, Alexander Z.,Thorn, David L.,Glover, Gerald V.
scheme or table, p. 8673 - 8674 (2009/04/11)
(Chemical Equation Presented) A general synthesis for the preparation of alkyl N,N′-β-diketimines has been developed. The method reported here demonstrates the use of dimethyl sulfate for conversion of enaminoketones to β-diketimines. The reaction can be performed without solvent, providing good yields.
Pyrrole and Pyrazole Ring Closure in Heterogeneous Media
Texier-Boullet, F.,Klein, B.,Hamelin, J.
, p. 409 - 411 (2007/10/02)
Pyrroles and pyrazoles may be conveniently prepared by dispersing primary amines or hydrazines and 1,4- or 1,3-diketones, respectively, on alumina or clay (montmorillonite K 10) without solvent, keeping the mixture at 20 deg C or higher temperatures for 1-26 h, and then eluting the product with dichloromethane.
