Synthesis and characterization of metallodendritic palladium-biscarbene complexes derived from 1,1′-methylenebis(1,2,4-triazole)

摘要: The syntheses of first generation dendritic compounds bearing 1,1′-alkane-1,1-diylbis(4-butyl-4,5-dihydro-1H-1,2,4-triazol-5-ylidene)palladium(II) dibromide on the periphery are described. metallabiscarbene moieties have also been studied separately from dendrimer. These display a non-symmetric boat-to-boat conformational equilibrium that has axial and equatorial arrangements. predominance conformer in is supported by DFT calculations. X-ray solid state structures conformers 3-hydroxy- 3-mesyloxy-1,1′-propane-1,1-diylbis(4-butyl-4,5-dihydro-1H-1,2,4-triazol-5-ylidene)palladium(II) reported. complexes modest catalytic activity Heck reaction with activated aryl bromides catalysts were more active than corresponding non-dendritic mononuclear species, finding indicative cooperative effect.