Electrostatic repulsion-controlled regioselectivity in nitrene-mediated allylic C-H amidations

The mechanism and origin of regioselectivity of nitrene-mediated allylic C-H amidations were computationally investigated. The allylic C-H activation via CMD mechanism represents the rate-determining step. The nitrene insertion step based on the formed allyl-Ir-nitrene determines the regioselectivity. Based on the distortion/interaction model and energy decomposition analysis, the repulsive electrostatic interaction between negatively charged nitrene N and allyl terminal C atoms is identified as the dominant factor controlling the regioselectivity.