Synthesis and characterization of orthopalladated complexes containing tridentate C,N,O-oxazolones

The (Z)-4-aryliden-2-(2-acetoxyphenyl)-5(4H)oxazolones 1a-1c react with H2SO4 to give the corresponding (Z)-4-aryliden-2-(2-hydroxyphenyl)-5(4H)oxazolones 2a-2c.The molecular structures of 1c and 2a have been determined by X-ray diffraction methods, show planar skeletons. Oxazolones 2a-2c are potential C,N,O-tridentate ligands towards transition metals, their design obeys search a rigid environment around metal. reaction Pd(OAc)2 oxazolones (1:1 M ratio) in CF3CO2H or NCMe as solvents results synthesis diverse complexes (3–7). As function conditions, two different bonding modes characterized: N,O-chelate dinuclear [Pd(κ2-N,O-2b,c)(μ -O2CCF3)]2 (3b,c), result N-coordination deprotonation hydroxy group; mononuclear [Pd(κ 3-C,N,O-2a,b)(L)] (L = 4a,b; dmso-d6 5a,b; 6b; pyridine 7b), obtained after N-bonding, OH CH bond activation. All fully characterized HRMS NMR showing high stability mode.