The chemistry of small‐ring compounds. Part 40. Protonated and methylated methyleneaziridines

Abstract

Abstract The N ‐substituted methyleneaziridines 1a‐c are protonated on nitrogen without ring rupture by HFSO 3 /SbF 5 in SO 2 at − 78°C. NMR spectra remain unchanged up to + 50°C. Methylation of la does not take place with ordinary methylating agents but can be achieved with (CH 3 ) 2 Cl ⊕ SbF 5 Cl ⊖ .