A theoretical study of the influence of nitrogen angular constraints on the properties of amides: Rotation/inversion barriers and hydrogen bond accepting abilities of N-formylaziridine and -azirine

Abstract

Theoretical calculations at the MP2/6-311++G** level have been carried out on three compounds: N,N-dimethylformamide (1), N-formylaziridine (2) and N-formylazirine (3). The barriers to rotation and inversion have been calculated, together with the properties of the nitrogen and oxygen atoms of these amides as hydrogen bond acceptors. The results provide a quantitative picture of the influence of ring strain on the properties of amides, with special emphasis on the effects associated with nitrogen pyramidalization. © The Royal Society of Chemistry and the Centre National de la Recherche Scientifique 2005.