Highly Selective Benzylic C-H Bond Activation of Toluene by 'Bare' FeO(1+) in the Gas Phase

Article abstract of DOI:10.1002/hlca.19920750605

The reaction of FeO(1+) with toluene in the gas phase occurs at collision rate (k_r = 1.36*10^-9 cm³ molecule^-1 s^-1), and labeling experiments demonstrate that the total products due to C-H bond activation involve to > 92percent the benzylic position.In the 'hydride' abstraction process (formation of FeOH and C7H7(1+)), the H-atom originates exclusively from the benzylic position to generate a benzyl cation, and an intramolecular kinetic isotope effect k_H/k_D = 1.75 has been obtained.There is no evidence for the existence of isotopically sensitive branching ('metabolic switching') in the system studied.