Deacetylation of gaseous amidoalkylating reagents (N‐acyliminium ions) via iminium/ketene complexes: An unprecedented isotope effect

Abstract The prototype amidoalkylating reagent, the N ‐acetylmethyliminium ion CH 3 C(O)N(H)CH 2 + (a), was generated in the gas phase and its unimolecular chemistry was studied. Metastable ions a dissociate by deacetylation to CH 2 NH 2 + with an exceedingly small translational energy release (0.03 kJ mol −1 ). A remarkable ‘all‐or‐nothing’ deuterium isotope effect is associated with this reaction. Hence although the deuterium‐labelled …