Abstract
The prenyl group is present in numerous biologically active small molecule drugs and natural products. We introduce benzylic C-H alkenylation of substrates Ar-CH(3) with alkenylboronic esters (CH(2))(3)O(2)B-CH[double bond, length as m-dash]CMe(2) as a pathway to form prenyl functionalized arenes Ar-CH(2)CH[double bond, length as m-dash]CMe(2). Mechanistic studies of this radical relay catalytic protocol reveal diverse reactivity pathways exhibited by the copper(ii) alkenyl intermediate [Cu(II)]-CH[double bond, length as m-dash]CMe(2) that involve radical capture, bimolecular C-C bond formation, and hydrogen atom transfer (HAT).