C-H Acidity and Arene Nucleophilicity as Orthogonal Control of Chemoselectivity in Dual C-H Bond Activation.

We discovered a cooperative gold/silver catalysis mechanism in the oxidative cross-coupling reaction between 1,2,4,5-tetrafluorobenzene and N-TIPS-indole, using DFT calculations. A silver(I)-catalyzed CMD mechanism is responsible for the C-H activation of 1,2,4,5-tetrafluorobenzene, and C-H acidity determines the chemoselectivity. A gold(III)-catalyzed S2Ar mechanism is responsible for the C3-H activation of N-TIPS-indole, and arene nucleophilicity determines the chemo- and regioselectivity. The orthogonal chemoselectivity control provides a mechanistic guide for dual C-H activation reactions.