RECENT PROGRESS IN THE SYNTHESIS OF NITROPYRAZOLES AND THEIR HYDROGENATED ANALOGS <i>VIA</i> NONCATALYZED (3+2) CYCLOADDITION REACTIONS OF CONJUGATED NITROALKENES

Radomir Jasiński

RECENT PROGRESS IN THE SYNTHESIS OF NITROPYRAZOLES AND THEIR HYDROGENATED ANALOGS <i>VIA</i> NONCATALYZED (3+2) CYCLOADDITION REACTIONS OF CONJUGATED NITROALKENES

Authors

Radomir Jasiński Cracow University of Technology, Department of Organic Chemistry and Technology, 24 Warszawska St., 31-155 Cracow

Keywords:

nitroalkenes, nitropyrazoles, pyrazoles, (3+2) cycloaddition

Abstract

In this mini-review, the application of noncatalyzed (3+2) cycloaddition reactions for the selective preparation of nitropyrazoles and their hydrogenated analogs is analyzed based on recent literature. Generally, the preparation of the title compounds via (3+2) cycloaddition protocol is feasible using three types of three-atom components: diazo compounds, nitrylimines, and azomethine imines. It was found that nearly all processes discussed were carried out with high or full selectivity also at room temperature.