Paradigms and Paradoxes: The Energetics of N-Acylimines

Three-membered ring amides — a calculational and conceptual study of the structure and energetics of 1,2-oxaziridine-3-one and aziridine-2,3-dione

Species with three-membered rings and the amide linkage are well studied. A quick perusal of the literature with SciFinder finds some 50 000 references to cyclopropanes and almost 300 000 references to amides. In the current paper, we discuss the structure and energetics of two understudied three-membered ring amides, 1,2-oxaziridine-3-one (5) (simultaneously describable as the simplest cyclic carbamate and simplest hydroxamate) and aziridine-2,3-dione (7) (simultaneously describable as the simplest imide and simplest α-ketoamide), with but 5 and nearly 10 references, respectively, for these two classes of compounds. Neither 1,2-oxaziridine-3-one (5) nor aziridine-2,3-dione (7), nor any derivative thereof, has been isolated. Calculational theory ameliorates the paucity of experimental information. The current study reports our computational findings for these and related species (e.g., enols and imidols) where we have used the G3(MP2)//B3LYP method.

Solid-State Photolysis of α-Azidoacetophenones

Solid-state photolysis of 1 yields 2 in a crystal-to-crystal reaction. The reaction takes place by alpha-cleavage to form a benzoyl and an azido alkyl radical pair. The azido alkyl radicals rearrange into iminyl radicals and N2. The iminyl and benzoyl radicals are held in close proximity within the crystal lattice, which allows them to combine and form 2. X-ray structure analysis, molecular modeling and trapping studies support this mechanism.