A panel of natural aliphatic tertiary alkaloids (R₃N) were directly converted to R₃N⁺–NH⁻ (without the need to prepare protected aminimides R₃N⁺–NR′⁻ followed by deprotection) by [Mn(TDCPP)Cl]-catalysed N-amination reaction, with O-(2,4-dinitrophenyl)hydroxylamine as the nitrogen source, in up to 98% yields under mild reaction conditions.