Selectivity in reductive elimination from dialkyl(aryl)palladium(IV) complexes, and the observation of benzyl halide transfer from palladium(IV) to palladium(II). The X‐ray structure of methyl(phenyl)(2,2′‐bipyridyl)palladium(II)
作者
Bertus A. Markies,Maurits D. Janssen,Jaap Boersma,Gerard van Koten,Allan J. Canty,Anthony L. Spek
Abstract The first arylpalladium(IV) complexes, [PdXMePhR(bpy)] (bpy = 2,2′‐bipyridyl), have been isolated upon oxidative addition of methyl iodide or benzyl bromide to [PdMePh(bpy)]. These dialkyl(aryl)palladium(IV) complexes undergo reductive elimination in solution at ca. 0 °C: [PdBrMePh(CH2Ph)(bpy)] decomposes quantitatively into [PdBr(CH2Ph)(bpy)] and toluene whereas [PdIMe2Ph(bpy)] gives ethane and toluene in 4: 1 ratio together with the corresponding complexes [PdIR(bpy)] (R = Me or Ph). The reaction of methyl iodide with [PdMePh(tmeda)] at 0 °C yields ethane and [PdIPh(tmeda)] without detection of a palladium(IV) intermediate. No reaction of [PdMePh(tmeda)] with benzyl bromide was observed. The first demonstration that organic groups can be transferred from palladium(IV) to palladium(II) is reported. The molecular structure of [PdMePh(bpy)] in the solid state has been determined.