Hydrocarbon C-H Bond Activation with Tp'Pt Complexes

摘要

Stabilization of platinum complexes resembling key intermediates in C-H bond activation has been achieved through the use of the strongly electron-donating hydridotris(3,5-dimethylpyrazolyl)borate (Tp') ligand. Isolation of stable alkyl(hydrido)platinum(IV) complexes, Tp'PtMe_2H and Tp'PtMeH_2) allowed us to investigate the mechanism of reductive alkane elimination from these complexes via (1) thermolysis, (2) Lewis acid addition, and (3) low temperature protonation. By replacing the alkyl group with SiRj and C6R.5 in the low temperature protonation of Tp'PtRH_2, isolation of five-coordinate Pt(IV) complexes and Pt(II) η~2-arene adducts, respectively, was achieved. These Pt(II)/Pt(IV) interconversions provide insight into the mechanisms by which these reagents activate strong C-H bonds and also provide a foundation for future plans to functionalize hydrocarbons.