Direct C—H functionalization of quinoline N-oxides with arylboronic acids is achieved using KMnO_4 as the sole and efficient oxidative system.This method provides an efficient protocol to construct regioselectively 2-arylquinoline N-oxides via radical cross-coupling reaction in moderated to good yields under mild conditions. Direct C-H functionalization of quinoline N-oxides with arylboronic acids is achieved using KMnO_4 as the sole and efficient oxidative system. This method provides an efficient protocol to construct regioselectively 2-arylquinoline N-oxides via radical cross-coupling reaction in moderated to good yield under mild conditions.