Abstract:

The synthesis of pyrazoles has been the subject of consistent interest because of the wide applications for such heterocycles. Nevertheless the synthesis of such compounds with unsymmetrical 1,3-dicarbonyl substrates often produces a regioisomeric mixture of pyrazoles with generally poor selectivity. However, Rosa and co-workers reported the regiospecific synthesis of pyrazole-5-carboxylates from unsymmetrical enaminodiketones. Thus, considering the application of pyrazoles and the regiospecificity of the reactions presented by Rosa, we conducted a detailed theoretical investigation of the structure of the reagents, products and possible transition states in the reactions (Figure 1).