Oxidative aminoaziridination: past, present, and future

Thermal Ring Expansion of 2‐Sulfonylimidoyl‐1‐phthalimidoaziridines into N‐Sulfonylimidazoles

“…However, at –20 °C, as determined by the 1 H NMR spectrum of 3d , the signal of the minor form at δ = 5.90 (H 2 ) is already a typical narrow doublet. The values of vicinal coupling constants of 3 J = 4.6–4.8 Hz for the main invertomers and 5.3–5.5 Hz for the minor ones correspond to the trans ‐arrangement of the aziridine ring protons, which is consistent with the well‐known retention of the double‐bond configuration in oxidative aminoaziridination reactions . This result is also confirmed by the X‐ray diffraction analysis of 3f (Figure ).…”

Pyrazoles and C‐Imidoylaziridines through [4+1] Annulation and [2+1] Cycloaddition of 1‐Azabuta‐1,3‐dienes with a Synthetic Equivalent of Phthalimidonitrene

“…Values of the vicinal coupling constants ( 3 J = 5.2–5.8 Hz) indicate a trans arrangement of the protons in the aziridine ring in all three forms of both compounds. This is consistent with the well‐known retention of configuration of the double bond in oxidative aminoaziridination reactions . The signals of the aziridine carbon atoms in the 13 C NMR spectra appear at δ = 50.8 (51.1) (C 3 ), 52.3 (52.2) (C 2 ) ppm for the major form, at δ = 47.2 (47.2) (C 2 ), 52.8 (53.0) (C 3 ) ppm for the first minor isomer, and at δ = 42.6 (42.8) (C 2 ), 51.7 (51.7) (C 3 ) ppm for the second minor isomer.…”

“…In contrast, reactions of 1‐azadienes with aziridinating reagents are scarce and include only the copper‐catalyzed aziridination of the N ‐substituted hydrazones of α,β‐unsaturated aldehydes as well as the aminoaziridination of the phthaloyl hydrazone of cinnamic aldehyde . Because oxidative addition of N ‐aminophthalimide to C=C bonds is a convenient approach to N ‐phthalimidoaziridines with a different substitution pattern from that highlighted above, we set out to explore if 2‐imidoyl‐1‐phthalimidoaziridines could be prepared from 1,2,4‐triaryl‐1‐azabuta‐1,3‐dienes (Scheme ). Previously, we obtained azoaziridines and 2 H ‐1,2,3‐triazoles from conjugated azoalkenes (i.e., 1,2‐diazabuta‐1,3‐dienes) through the in situ oxidation of N ‐aminophthalimide by lead tetraacetate .…”

Recent Advances in the Chemistry of 2-Acylaziridines

“…2-Acyl-1-phthalimidoaziridines 1, which were obtained via oxidative aminoaziridination 4 of α,β-unsaturated ketones, give rise to 2,5-disubstituted oxazoles 5 upon heating (Scheme 1). Electron-donating substituents in the aryl fragment accelerate the conversion into oxazoles, but similar substituents in the aroyl fragment inhibit this transformation.…”