Fluoride-activated silicon catalysis enables C(sp3)-H amination of cyclic benzylic ethers and amines using chloramine-T.

Fluoride-activated silicon catalysis enables radical benzylic C(sp3)-H amination of cyclic benzylic ethers and amines with bench-stable chloramine-T under transition-metal-free conditions. Mechanistic studies support a previously unexplored fluoride-promoted silicon catalytic cycle involving N-silyl sulfonamide intermediates, radical-mediated hydrogen-atom transfer, oxocarbenium ion formation for N,O-aminals, and iminium ion formation for N,N-aminals, providing an efficient platform for direct benzylic C-N bond formation.