Scientists from ZIOC have studied the reaction of donor-acceptor cyclopropanes with 5-aminopyrazoles

Donor-acceptor cyclopropanes are polyfunctional compounds exhibiting a wide spectrum of reactivity. The Laboratory of Directional Functionalization of Organic Molecular Systems of the Zelinsky Institute is actively studying new facets of the reactivity of donor-acceptor cyclopropanes. In one of their latest works, scientists studied the reaction of these compounds catalyzed by Lewis acids with 1,3-disubstituted 5-aminopyrazoles, which can act as ambident nucleophiles and attack electrophilic centers with both the amino group and the C-4 carbon atom. It was found that the direction of the reaction depended both on the structure of the starting cyclopropane and on the process conditions. In the presence of gallium (III) chloride as a Lewis acid, cyclopropane is attacked nucleophilically by the exocyclic nitrogen atom of aminopyrazole, and in the case of scandium (III) triflate, attack by both the nitrogen atom and the C-4 carbon atom can occur. As part of the study, the obtained products were also converted into derivatives of 2-pyrrolidone and azepinone, which are of interest for medicinal chemistry and pharmacology.
 

Source:

Anna E. Vartanova, Irina I. Levina, Nina K. Ratmanova, Ivan A. Andreev, Olga A. Ivanova, Igor V. Trushkov Ambident reactivity of 5-aminopyrazoles towards donor–acceptor cyclopropanes // Org. Biomol. Chem., 2022,20, 7795-7802. DOI: 10.1039/d2ob01490d.