Synthesis of α-Aminocyclopropyl Ketones and 2-Substituted Benzoimidazoles from 2-Hydroxycyclobutanones and Aryl Amines

We have developed one-step protocols for the preparation of a large selection of α-aminocyclopropyl ketones or benzo[d]imidazoles, by reacting 2-substituted-2-hydroxycyclobutanones with aryl amines or o-phenylenediamines, respectively. In most case the reactions proceed at room temperature and are catalyst-free. The formation of benzo[d]imidazoles is rationalized in terms of an unusual ring-closure/ring-fission process followed by aromatization. (Figure presented.).