55213-06-4Relevant 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)
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.
P2W18O62·24H2O as an efficient and recyclable catalyst for the ecofriendly preparation of β-aminocrotonates
Sanchez, Laura M.,Sathicq, Angel G.,Baronetti, Graciela T.,Thomas, Horacio J.,Romanelli, Gustavo P.
, p. 137 - 142 (2013/06/05)
H6P2W18O62·24H 2O bulk-and silica-supported catalysts were found to be efficient and recyclable catalysts for the synthesis of a series of β-aminocrotonates using toluene as the solvent or under no solvent reaction conditions. Several substituted β-aminocrotonates can be prepared in very good yields and purity by direct reaction of amines and 1,3-dicarbonyl compounds in the presence of a catalytic amount of bulk-and silica-gel-supported H6P 2W18O62·24H2O. The title compounds were prepared in very good yields using both methodologies, and no secondary products were detected. The procedure using no reaction solvent resulted in a clean and useful alternative, which has the advantages of a greener methodology with operative simplicity, the use of a reusable and noncorrosive solid catalyst, soft reaction conditions, low reaction times, and good yields.
Ecofriendly and facile Nano ZnO catalyzed solvent-free enamination of 1,3-dicarbonyls
Indulkar, Utkarsha U.,Kale, Sandip R.,Gawande, Manoj B.,Jayaram, Radha V.
supporting information; experimental part, p. 3857 - 3860 (2012/08/27)
Nano zinc oxide (Nano-ZnO) was explored as a reusable catalyst for the enamination of 1,3-dicarbonyls using diverse amines. To make the process environmentally viable, the reaction was carried out under solvent-free conditions and found to give good yield of desired products. The catalyst was characterized by various analytical techniques such as UV-spectroscopy, XRD, and TEM. The catalyst was found to be reusable up to four catalytic cycles without any appreciable loss in activity.
