Palladium-Catalyzed C–H Activation/Cross-Coupling of Pyridine N‑Oxides with Nonactivated Secondary Alkyl Bromides

An unexpected C–H activation/C–C cross-coupling reaction has been found to occur between pyridine N-oxides and general nonactivated secondary and even tertiary alkyl bromides. It provides a practically useful approach for the synthesis of alkylated pyridine derivatives. Experimental observations indicated that the C–Br cleavage step involves a radical-type process. Thus, the title reaction provides a rather extraordinary example of Pd-catalyzed cross-coupling of secondary and tertiary aliphatic electrophiles.