C-H bond activation by dicationic platinum(II) complexes

Article abstract of DOI:10.1021/om060792r

Double protonolysis of diimine platinum dimethyls [(N-N)PtMe₂] (N-N = ArN=C(Me)C(Me)=NAr) generates dicationic Pt(II) complexes that can activate a variety of C-H bonds, liberating 1 equiv of acid and forming organoplatinum species that are moderately stable to the resulting acidic conditions. Ethylbenzenes lead to η³-benzyl complexes; mechanistic experiments suggest that η³-benzyl product formation proceeds via C-H bond activation at the benzylic methylene position. In some cases π-arene complexes can be observed, but their role in the C-H activation process is not clear. Cyclohexane and 1-pentene react to give η³-allyl complexes; allylbenzene gives a chelated phenyl-)η²-olefin structure, as determined by X-ray diffraction. No stable C-H activation products are obtained from methylbenzenes, benzene itself, or alkanes.