Preparation of Ni- or Pt-Containing Cyclic Esters by Oxidative Addition of Cyclic Carboxylic Anhydrides and Their Properties

Article abstract of DOI:10.1246/bcsj.57.2741

Metal containing cyclic ester complexes, L<*> (L=1,2-bis(diphenylphosphino)ethane (dpe) or 2,2'-bipyridine (bpy); R¹, R²=H or CH₃) and L_n<*> )L=tricyclohexylphosphine (PCy₃) or dpe; n=1 or 2), have been prepared by oxidative addition of cyclic carboxylic anhydrides to zero-valent metal complexes.These complexes have been characterized by elemental analysis and spectroscopies (IR as well as ¹H-, ¹³C<¹H>-, and ³¹P<¹H>-NMR) and chemical rectivities.Rate of the oxidative addition of succinic anhydride to Ni(bpy)(cod) (cod=1,5-cyclooctadiene) is expressed by a second order rate equation, R=k, and temperature dependence of k gives the activation energy of 68 kJ mol^-1.The reaction of methylsuccinic anhydride with Ni(cod)₂ in the presence of tertiary phosphine or bpy affords two isomers, L_n<*> and L_n<*>, corresponding to two modes of C-O bond cleavage in methylsuccininc anhydride promoted by Ni; dependence of the ratio between the two isomers on the kind of ligand added and reaction conditions has been examined.