C−H Bond Activation by Unsymmetrical 2-(<i>N</i>-Arylimino)pyrrolide Pt Complexes: Geometric Effects on Reactivity

Reactions of chloroplatinum methyl complexes with N-(arylimino)pyrrolide anions afford cis and trans neutral platinum methyl complexes. Isomers with methyl trans to the pyrrolide nitrogen activate benzene C−H bonds at 85 °C more than 80 times faster than the corresponding cis isomer. In addition, reactions of platinum dimethyl complexes with N-(arylimino)pyrroles (Ar = 4-substituted phenyl) in C6D6 at ambient temperature give unlabeled methane and cis methyl complex containing heavily deuterated Pt−Me. In contrast, bulky aryl substituents give methane isotopomers and trans-Pt−Ph product. The origins of these observations are discussed.