Oxime‐Derived Palladacycles: Applications in Catalysis

Abstract

Abstract:Phenone oxime-derived palladacycles are stable, easy to prepare and excellent source of three-and four-atom Pd clusters able to show excellent catalytic activity in most of the classical carbon-carbon bond forming reactions (Mizoroki-Heck, Matsuda-Heck, Suzuki-Miyaura, Stille, Kumada, Hiyama, Ullmann, Sonogashira and Glasser) in general with better performance than Pd(OAc)2 or other Pd salts. Aryl iodides, bromides, chlorides and imidazolyl sulfonates can be used as substrates not only in organic solvents but also in aqueous solvents including neat water. Appropriate general reaction conditions are found to perform efficiently these C-C bond forming reactions. They have been also used in carbonylations, several types of annulations, ketone arylations, C-H activation, oxime rearrangements and behave as metalloenzymes in hydrolytic processes among others. Not only dimer complexes can be used but also monomer ones with an additional ligand as well as supported on polymers, silica, and bearing ionic or fluorinated tags.

Oxime palladacycle in PEG as a highly efficient and recyclable catalytic system for phenoxycarbonylation of aryl iodides with phenols

“…The plausible reaction mechanism of oxime palladacycle (1) catalyzed phenoxycarbonylation for ester synthesis is shown in Scheme . Initially, Pd (0) insert between aryl iodide via breaking of C‐I bond to the formation of species B . Then CO (g) coordinate with aryl palladium species ( B ) to give C .…”

Graphene Oxide-Supported Oxime Palladacycles as Efficient Catalysts for the Suzuki–Miyaura Cross-Coupling Reaction of Aryl Bromides at Room Temperature under Aqueous Conditions

“…1 H-NMR (300 MHz) and 13 C-NMR (75 MHz) spectra were obtained on a Bruker AC-300, using CDCl3 as solvent and TMS (0.003%) as reference, unless otherwise stated. Low-resolution mass spectra (MS) were recorded in the electron impact mode (EI, 70 eV, He as carrier phase) using an Agilent 5973 Network Mass Selective Detector spectrometer, being the samples introduced through a GC chromatograph Agilent 6890N equipped with a HP-5MS column [(5%-phenyl)-methylpolysiloxane; length 30 m; ID 0.25 mm; film 0.25 mm].…”

“…Carbometallated Pd(II) compounds, especially the highly active palladacycles [10][11][12][13], have emerged as very promising catalysts for C-C bond forming reactions. These complexes usually involve very low catalyst loadings, minimizing the cost-effective impact of the expensive palladium.…”

Efficient and green catalytic system incorporating new benzimidazolium salts for the Sonogashira cross‐coupling reaction

“…Immobilization is a method to improve catalytic activity and recyclability of homogeneous catalysts using an appropriate supporting system such as polymers, resins etc. [39][40][41][42] However, it has been reported that palladium immobilization is generally complicated and involves multiple steps with undesirable palladium black formation and relatively long reaction times. [40,41] In our previous work, we investigated the catalytic activity of N-phthalimidoethyl and 4-substituted benzylbearing benzimidazolium salts in the Sonogashira crosscoupling reaction.…”