Recent advances in the multicomponent synthesis of pyrazoles have been reviewed. The reactions involving hydrazine, hydrazine, diazo compound, and nitrile/amine as N
N donors are summarized.
The past decade has witnessed significant progress in synthesizing structurally diverse and biologically relevant pyrano[2,3-c]pyrazole derivatives through the integration of green methodologies.
A novel and efficient cerium-catalyzed tandem oxidation and intermolecular ring cyclization of vicinal diols with hydrazones has been achieved for the regioselective synthesis of pyrazole derivatives.
A cycloaddition protocol that enables the regioselective synthesis of 3,4-diarylpyrazole and, for the first time, 3,4-diheteroaryl analogs is reported. The procedure employed mild conditions and easy to prepare starting materials.
A conceptual overview and discussions are presented to showcase the synthesis of five-membered heteroaromatics and related drugs using emerging toolboxes (photochemical synthesis, electrocatalysis and biocatalysis).