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, and show planar skeletons. Oxazolones 2a-2c are po...

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Detalles Bibliográficos
Autores: Dalmau, David, Jiménez, Ana I., Urriolabeitia, Esteban P.
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2022
País:España
Institución:Consejo Superior de Investigaciones Científicas (CSIC)
Repositorio:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/284680
Acceso en línea:http://hdl.handle.net/10261/284680
Access Level:acceso abierto
Palabra clave:Oxazolones
NMR spectroscopy
C-H bond activation
X-ray diffraction
Pd(II) complexes
Descripción
Sumario: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, and show planar skeletons. Oxazolones 2a-2c are potential C,N,O-tridentate ligands towards transition metals, and their molecular design obeys to the search of a rigid environment around the metal. The reaction of Pd(OAc)2 with oxazolones 2a-2c (1:1 M ratio) in CF3CO2H or NCMe as solvents results in the synthesis of diverse complexes (3–7). As a function of the reaction conditions, two different bonding modes have been characterized: N,O-chelate in the dinuclear complexes [Pd(κ2-N,O-2b,c)(μ -O2CCF3)]2 (3b,c), as a result of the N-coordination and deprotonation of the hydroxy group; and C,N,O-tridentate in mononuclear complexes [Pd(κ 3-C,N,O-2a,b)(L)] (L = CF3CO2H 4a,b; dmso-d6 5a,b; NCMe 6b; pyridine 7b), obtained after N-bonding, OH deprotonation and Csingle bondH bond activation. All complexes have been fully characterized by HRMS and NMR methods, showing the high stability of the C,N,O-tridentate bonding mode.