Organopalladium(IV) Chemistry: Oxidative Addition of Organohalides to Dimethylpalladium(ii) Complexes to form Ethyl, sigma-Benzyl, and sigma-Allylpalladium(IV) Complexes

The first examples of ethyl, sigma-benzyl, and sigma-allylpalladium(IV) complexes are formed on oxidative addition of organo ha1ides to PdMe2{(pyrid in-2-yl)bis(N-methyIimidazoI-2-yl)methane} [PdMe2{(py)(mim)2CH}]; the complexes [fac-PdRMe2{(py)(mim)2CH-N,N',N }]X (RX = Etl PhCH2Br CH2=CHCH2Br) are stable at ambient temperature with the cations present as two isomers and benzyl bromide also forms the neutral complex fac-Pd(CH2Ph)Me2(bipy)Br on oxidative addition to PdMe2(22'-bipyridyl) but Etl and CH2=CHCH2Br form transient Pd(IV) species detectable by 1H n.m.r. spectroscopy prior to reductive elimination reactions."