1133330-69-4Relevant articles and documents
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)
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
Imidazolyl-Functionalized Ordered Mesoporous Polymer from Nanocasting as an Effective Support for Highly Dispersed Palladium Nanoparticles in the Heck Reaction
Karimi, Babak,Marefat, Mohammad Reza,Hasannia, Maliheh,Akhavan, Pari Fadavi,Mansouri, Fariborz,Artelli, Zahra,Mohammadi, Fariba,Vali, Hojatollah
, p. 2508 - 2515 (2016/08/25)
New imidazolyl-functionalized ordered mesoporous cross-linked polymers were prepared by the copolymerization of the ionic liquid 3-benzyl-1-vinyl-1H-imidazolium bromide with divinylbenzene as the cross-linker and azobisisobutyronitrile as the radical initiator in the presence of O-silylated SBA-15 as the hard template. The materials were characterized by N2 adsorption–desorption analysis, TEM, thermogravimetric analysis, elemental analysis, and FTIR spectroscopy. The material, which benefits from the use of entrapped ionic liquid in the prepared polymer matrix in combination with its ordered mesoporous structure, is an excellent environment for the stabilization of highly dispersed Pd nanoparticles to result in a recyclable catalyst system with a significant activity in the Heck coupling reaction of aryl halides. The presence of well-distributed imidazolium functionalities in the polymeric framework might be responsible for the relatively uniform and nearly atomic scale distribution of Pd nanoparticles throughout the mesoporous structure and the prevention of Pd agglomeration during the reaction, which results in high durability, high stability, and good recycling characteristics of the catalyst. Although our catalyst system operates in a homogeneous pathway, it is also very stable and recyclable.
Iminophosphine palladium(II) complexes: Synthesis, characterization, and application in Heck cross-coupling reaction of aryl bromides
Yilmaz, Mustafa Kemal,Guezel, Bilgehan
, p. 529 - 536 (2014/07/07)
Palladium(II) complexes containing phosphorus and nitrogen donor atoms (iminophosphine), dichlorido{N-[2-(diphenylphosphino)benzylidene]-2- trifluoromethylaniline}palladium(II) 1, dichlorido{N-[2-(diphenylphosphino) benzylidene]-3-trifluoromethylaniline}palladium(II) 2, dichlorido{N-[2- (diphenylphosphino)benzylidene]-2-methylaniline}palladium(II) 3, dichlorido{N-[2-(diphenylphosphino)benzylidene]-3-methylaniline}palladium(II) 4 have been successfully synthesized and fully characterized by FT-IR and NMR (1H, 31P, 19F, and 13C) spectroscopy techniques. These complexes were first step tested in the reaction of bromobenzene and styrene to determine the optimal coupling reaction conditions and then successfully applied as catalysts for Heck cross-coupling reactions of activated and deactivated aryl bromides with styrene derivatives and several acrylates. Copyright
