Asymmetric nitrogen. 73. Geminal systems. 47. Configuration stability and mechanism for inversion of N-chloroxaziridines

We have studied the kinetics of racemization and thermolysis of (+)-2-chloro-3,3-pentamethyleneoxaziridine (I). The activation energy determined for inversion of the nitrogen atom in (I) in n-heptane is 28.9 kcal/mole lower than the value calculated (ab initio, 3–21G) for 2-chloroxaziridine (II). Based on this and also on the increase in the inversion rate of (I) with an increase in the polarity of the solvent and the entropy of activation (–43.5 cal/mole·K, n-heptane), we conclude that the mechanism for inversion of N-chloroxaziridines is nonclassical, by means of reversible ionization of the N-Cl bond through a solvate-unseparated ion pair.For the previous communication, see [1].Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 8, pp. 1816–1819, August, 1989.