tert-Butyl Peroxybenzoate (TBPB)-Mediated 2-isocyanobiaryl Insertion with 1,4-Dioxane: Efficient Synthesis of 6-Alkyl Phenanthridines via C(sp3)—H/C(sp2)—H Bond Functionalization.

An efficient method for the construction of 6-alkyl phenanthridines by tert-butyl peroxybenzoate (TBPB)-mediated 2-isocyanobiaryl insertion with 1,4-dioxane was established. Two new C–C bonds were formed in this reaction via a sequential C(sp3)–H/C(sp2)–H bond functionalization under metal-free conditions.