Redox activation of alkene ligands in platinum complexes with non-innocent ligands.

Overview

The reactivity of metal olefin complexes with non-innocent ligands (NILs) was examined. Treatment of PtCl(2)(diene) with the deprotonated catechol or aminophenol ligands afforded the corresponding Pt(NIL)(diene) complexes. The Pt((t)BA(F)Ph)(COD), Pt((t)BA(F)Ph)(nbd), and Pt(O(2)C(6)H(2)(t)Bu(2))(COD) (H(2)(t)BA(F)Ph = 2-(2-trifluoromethyl)anilino-4,6-di-tert-butylphenol, H(2)O(2)C(6)H(2)(t)Bu(2) = 3,5-di-tert-butylcatechol) complexes were examined by cyclic voltammetry. Treatment of Pt((t)BA(F)Ph)(COD) or Pt((t)BA(F)Ph)(nbd) with AgPF(6) afforded the imino-semiquinones [Pt((t)BA(F)Ph)(COD)]PF(6) or [Pt((t)BA(F)Ph)(nbd)]PF(6), respectively. The [Pt((t)BA(F)Ph)(COD)] complex was unreactive toward nucleophiles, whereas the oxidized derivative, [Pt((t)BA(F)Ph)(COD)]PF(6), rapidly and stereospecifically added alkoxides at the carbon trans to the phenolate. The Pt((t)BA(F)Ph)(COD), [Pt((t)BA(F)Ph)(COD)]PF(6), Pt((t)BA(F)Ph)(C(8)H(12)OMe), and [Cp(2)Co][Pt((t)BA(F)Ph)(C(8)H(12)OMe)] complexes were characterized crystallographically.