Synthetic applications and mechanism study of the dealkenylative C–C bond functionalization. (a) A gram-scale reaction with substrate 23 under standard conditions. (b) Modification of some pharmaceutical derivatives by this C-C amination protocol. (c) Mechanistic studies for the determination of the reaction intermediate. The formation of 67 and 69 suggests that the imine 68 and 70 are involved as the intermediates. The transformation from 71 to 72 shows the possible benzylic cation intermediate. (d) Regiochemistry exploration for this process. (e) The proposed mechanism of this dealkenylative C-C functionalization.