Activated Aziridines. I. Reaction of Anilines with O-Ethyl-N,N-Ethyleneurethane. Mechanism and Hammett ρ-Constant

Aziridines: epoxides’ ugly cousins?

“…Protonation may activate aziridines to ringopening by relatively non-basic nucleophiles, but this, simplest, activating method is not appropriate for more basic nucleophiles, especially carbon-centred nucleophiles. Since the mid-1960s, aziridines have been classified as 'activated' or 'nonactivated' according to whether or not nucleophilic ring-opening reactions proceed in the absence of positive charge at nitrogen 12 and this classification is intimately related to the nature of the substituent at the nitrogen atom of the heterocycle. The rôle of activating group is often neatly filled by oxygenated substituents such as sulfonyl, sulfinyl, phosphoryl, phosphinyl or carbonyl functional groups (Fig.…”

Molecular conductance in relation to inverse transport theory and to chemical bond order

“…6) which differs from the more widely used Coulson bond order by inclusion of the energy denominator. Elsewhere, Ham 12 demonstrated that the Ruedenberg and Pauling bond orders R ij and P ij for neighbors i and j of a Kekulean benzenoid are equal. But unlike the Coulson bond order, Ruedenberg and Pauling forms are not defined in molecules that have occupied nonbonding orbitals (see also Ref.…”

The [Ru(CO)(porphyrin)]‐Catalyzed Synthesis of N‐Aryl‐2‐vinylaziridines

“…The chemical stability of a vinylaziridine largely depends on the nature of the substituent on its aziridine nitrogen, [32][33][34][35] with reactivity towards nucleophiles being promoted by the presence of an electron-withdrawing group on the nitrogen atom [3,34] whereas a rearrangement frequently occurs when a N-aryl group is present in the molecule. [36,37] Organic azides [38] -in particular sulfonyl [39,40] and aryl azides [41,42] -represent a versatile class of aminating agents.…”