30568-20-8Relevant academic research and scientific papers
Biogenic synthesis of palladium nanoparticles using Boswellia sarrata and their applications in cross-coupling reactions
Arde, Satyanarayan M.,Rashinkar, Gajanan S.,Jadhav, Sanjay N.,Patil, Audumbar D.,Salunkhe, Rajashri S.
, (2020)
A facile and green route for biogenic synthesis of palladium nanoparticles (PdNPs) using aqueous extract of nontoxic and renewable Boswellia sarrata leaves is reported. The as-synthesized PdNPs were systematically characterized by using ultraviolet (UV)–visible spectroscopy, X-ray diffraction analysis, scanning electron microscopy, transmission electron microscopy, energy-dispersive X-ray spectroscopy, and X-ray photoelectron spectroscopy. The PdNPs were crystalline and cubic in nature with average particle size of ~6 nm and successfully employed as heterogeneous catalyst in the Suzuki–Miyaura and Mizoroki–Heck cross-coupling reactions. The PdNPs could be recycled up to five times with modest change in the catalytic activity.
Flexible, dicationic imidazolium salts for in situ application in palladium-catalysed Mizoroki–Heck coupling of acrylates under aerobic conditions
Milton, Marilyn Daisy,Garg, Parul
, p. 759 - 766 (2016/09/04)
The synthesis, characterization and in situ catalytic performance of new unsymmetric N,N′-disubstituted imidazolium-based dicationic salts in Mizoroki–Heck coupling of acrylates with aryl bromides under aerobic conditions are described. A series of flexible dicationic salts with varying steric and electronic properties were synthesized in good to excellent yields. All the salts were well characterized using spectroscopic techniques. X-ray diffraction analysis of two salts with the same dicationic backbone and different counter anions shows that the ligand adopts two different conformations which are influenced by the nature of the anion. Thus, the ligand is capable of changing its conformation according to the change in environment due to its flexible nature. All the synthesized imidazolium salts were found to be active in in situ palladium-catalysed Mizoroki–Heck coupling under aerobic conditions. Amongst the salts, the hydroxyl-functionalized imidazolium salt, incorporating the features of both bidentate chelating O,O ligand and carbene, shows the maximum catalytic activity. A variety of aryl and heteroaryl methyl and ethyl cinnamates were synthesized using these imidazolium salts as preligands. In addition, NMR studies confirm in situ generation of normal N-heterocyclic carbenes from the C-2 position of imidazol-2-ylidene ring. The mercury poisoning test was also performed to ascertain the nature of catalytically active palladium species. Aerobic conditions, low catalytic loading (0.5?mol%), shorter reaction times, broad functional group tolerance and good to excellent isolated yields are some of the significant features of the novel catalytic systems described here. Copyright
