Ferrocenyl palladacycles derived from unsymmetrical pincer-type ligands: Evidence of Pd(0) nanoparticle generation during the Suzuki-Miyaura reaction and applications in the direct arylation of thiazoles and isoxazoles
A new family of ferrocenyl-palladacycle complexes Pd(L1)Cl (Pd1) and Pd(L2)Cl (Pd2) were synthesized and characterized by UV-visible, IR, ESI-MS, and NMR spectral studies. The molecular structures of Pd1 and Pd2 were determined by X-ray crystallographic studies. Palladacycle catalyzed Suzuki-Miyaura cross-coupling reactions were investigated utilizing the derivatives of phenylboronic acids and substituted chlorobenzenes. Mechanistic investigation authenticated the generation of Pd(0) nanoparticles during the catalytic cycle and the nanoparticles were characterized by XPS, SEM and TEM analysis. Direct C-H arylation of thiazole and isoxazole derivatives employing these ferrocenyl-palladacycle complexes was examined. The reaction model for the arylation reaction implicating the in situ generation of Pd(0) nanoparticles was proposed.
Direct C-H bond (Hetero)arylation of thiazole derivatives at 5-position catalyzed by N-heterocyclic carbene palladium complexes at low catalyst loadings under aerobic conditions
A highly efficient and practical protocol has been developed for the synthesis of 5-(hetero)arylated thiazole derivatives via an N-heterocyclic carbene palladium (Pd-NHC) complex catalyzed direct C-H arylation reaction. Utilization of this methodology, th
Developing Bis(imino)acenaphthene-Supported N-Heterocyclic Carbene Palladium Precatalysts for Direct Arylation of Azoles
On the basis of the strategy of developing highly efficient protocol for Pd-catalyzed cross-coupling reactions, a series of bulky bis(imino)acenaphthene (BIAN)-supported Pd-PEPPSI complexes were synthesized, characterized, and applied in direct arylation
Camphyl-based α-diimine palladium complexes: Highly efficient precatalysts for direct arylation of thiazoles in open-air
Based on the strategy of the development of phosphine-free palladium-catalyzed direct C-H arylation, a series of camphyl-based α-diimine palladium complexes bearing sterically bulky substituents were synthesized and characterized. The palladium complexes
A convenient phosphine-free palladium-catalyzed direct arylation of thiazole under mild aerobic conditions
A series of bulky amine palladium complexes {[(Ar-NH2)2PdCl2]} were synthesized and characterized. The catalytic activity of the palladium complexes was evaluated via the direct C-H arylation of thiazoles with aryl bromide
Palladium-catalyzed direct arylation of heteroaromatic compounds: Improved conditions utilizing controlled microwave heating
A versatile and rapid microwave-assisted procedure for the palladium-catalyzed direct arylation of heterocycles by aryl bromides and heteroaryl bromides is described. This novel protocol features short coupling times (10-60 min) and low catalyst loadings