Remote C(sp3)–H bond functionalization has traditionally been limited to carbon positions of n = 5–8 relative to the radical center via 1,n-hydrogen atom transfer (HAT) pathways. Functionalization at more distal sites (n > 8) has remained largely unexplored due to the insufficient spatial proximity of these C(sp3)–H bonds to the initiating radical. This work achieves regioselective C(sp3)–H bond functionalization of alkenes bearing C(sp3)–H bonds at the C6, C10, C11, and C15 positions via a metal- and catalyst-free strategy. A cascade of radical translocations enabled by successive 1,5-HAT events drives the transformation, facilitating selective C–H activation under mild conditions. Importantly, the in situ formation of the electron donor–acceptor (EDA) complex obviates the need for an external photocatalyst, enhancing the sustainability of the protocol. This method enables the efficient installation of diverse heterocycle motifs at previously inaccessible, remote C(sp3)–H sites, demonstrating broad functional group tolerance and affording products in moderate to excellent yields.
Srinivasu et al. (Sat,) studied this question.