The first example of oxyamination of azlactones with oxaziridines was realized using a chiral bisguanidinium salt. Efficient catalytic asymmetric oxyamination and kinetic resolution of oxaziridines occurred simultaneously. Various chiral oxazolin-4-one derivatives with potential biological activity were obtained (up to 92% ee). Meanwhile, a series of optically pure oxaziridines were recovered with up to 99% ee and successfully used in the asymmetric oxyamination of 3-methyl-1H-indole and styrene. The triple stereodifferentiation process was also studied via control experiments.