Information for details). The amination reaction of cyclopropylmethylbenzene (1ab) at standard conditions furnished a mixture of amination product 3ab and an ring-opening compound 16, thus supporting the presence of alkyl radical intermediate. A parallel kinetic isotope effect (KIE) study revealed a KIE of 2.1, indicating that the hydrogen atom abstraction of C-H by tert-butoxy radicals might be the rate limiting step for the reaction (Scheme 5B). Plotting log(er) against Hammett σp of benzamides showed a linear correlation between the enantioselectivity of the reaction and the electronic effect of the benzamide para-substituents (Scheme 5C). The negative slope of the plot indicated that the electron-rich amide is favorable for bonding with electron-deficient copper catalyst to form transient Cu(III) intermediates ligated by a benzyl and amide.