N-acyloxaziridines: characterization of both nitrogen inversion and N–C(O) bond rotation in an amido system

Abstract

Variable temperature ¹³C NMR investigations reveal that the N-acyl oxaziridine system can exhibit two independent stereodynamic processes: nitrogen inversion becomes slow on the NMR timescale at ca.–20 °C (ΔG^‡ 10.9–11.9 kcal mol^–1) and at ca.–60 °C rotation about the N–C(O) bond also becomes slow (ΔG^‡ 10.2 kcal mol^–1).