Kinetic and mechanistic studies of NEt₃-catalyzed intramolecular aminolysis of carbamate

(Graph Presented) The mechanism of the NEt₃-catalyzed intramolecular aminolysis of Z-1 in acetonitrile or aqueous acetonitrile solutions is suggested to involve rate-determining collapse of T ± through simultaneous H-abstraction and ethoxide expulsion of E2 process. The evidence for that includes the primary isotope effect of k_H/k _D, = 1.66 in acetonitrile, general-base catalysis in aqueous buffer solutions, salt effect, and the proposed water-stabilized rate-determining transition states (TS1 and TS2) in the water-titration experiments.