During the past few decades, intensive efforts have led to the development of useful chemical transformations which enable construction of complex molecular architectures from simple and readily available precursors. Catalytic C–H activation and subsequent formation of new C–C bonds (or C–heteroatom bonds) which avoids the use of pre-functionalized coupling partners, has remarkably contributed to development of such processes by shortening synthetic pathways and reducing waste production what makes it economically and ecologically more attractive in comparison with classical cross-couplings, i.e. Suzuki, Negishi, Kumada, etc.
Very recently, our research group has reported the first efficient synthesis of hexa(heteroaryl)benzenes by employing Ru(II)-catalyzed multiple C–H bond activation assisted by pivalate/PPh3 ligands while starting from simple heteroaryl precursors. Iterative penta-arylation could be implemented via activation of C–H bonds of generated intermediates by cascade chelation assistance of in situ installed pyridyl groups. The reactions proceeded with high selectivity under microwave irradiation, notably in water as the solvent.
Due to their unique propeller-like geometry and the presence of multiple coordination sites, hexa(heteroaryl)benzenes offer immense potential in catalysis, for application as molecular receptors and chemosensors, redox materials, photochemical switches, liquid crystalline materials as well as in construction of coordination architectures.
Ruthenium(II)-Catalyzed Microwave-Promoted Multiple C−H Activation in Synthesis of Hexa(heteroaryl)benzenes in Water
Microwave‐Promoted ortho‐C−H Bond (Hetero)arylation of Arylpyrimidines in Water Catalyzed by Ruthenium(II)−Carboxylate
