874534-74-4Relevant academic research and scientific papers
Mechanism of C-H bond activation of alkyl-substituted benzenes by cationic platinum(II) complexes
Driver, Tom G.,Day, Michael W.,Labinger, Jay A.,Bercaw, John E.
, p. 3644 - 3654 (2008/10/09)
While all methyl- and ethyl-substituted benzenes react with diimine Pt(II) methyl cations to give η3-benzyl products, they do not all get there by the same pathway. For toluene and p-xylene, isotopic labeling shows that initial activation occurs at aryl positions with subsequent intermolecular conversion to the benzyl product. For ethylbenzene and 1,4-diethylbenzene, initial activation takes place exclusively at aryl C-H bonds, and conversion to the η3-benzyl product takes place via intramolecular isomerization. Only in the most extreme case of steric crowding-the reaction of a bulky diimine platinum methyl cation (Ar = Mes) with triethylbenzene-does direct activation of the ethyl group become preferred to aryl activation.
