Synthesis, physical properties, and cytotoxicity of Nitroxyl-Aziridine hybrid

Nitroxyl-aziridine hybrid, a candidate for a magnetic resonance imaging (MRI) probe and an anticancer drug, was synthesized by aziridine formation reaction of nitroxyl-introduced aldehyde and guanidinium ylide in good diastereoselectivity. The relative configuration at aziridine C(2)-C(3) bond of the major diastereoisomer was determined to be cis by X-ray crystallographic analysis. Application of chiral guanidinium ylide resulted in the formation of the corresponding optically active aziridine in 84% ee. Reversible one-electron redox potential and quantitative spin yield of the hybrid were observed in cyclic voltammogram and electron spin resonance, respectively. However, cytotoxicity of the hybrid against cancer cell lines used was not observed.