Electrochemically Catalyzed N–N Coupling and Ring Cleavage Reaction of 1H-Pyrazoles

Abstract

The electrocatalyzed N–N coupling and ring cleavage reaction of 3-methyl-, 3,5-dimethyl-, 3-methyl-5-phenyl- and 3,5-diphenyl-1H-pyrazole was investigated and led to the electro-organic synthesis of new heterocyclic compounds. The results revealed that electrochemically produced 1H-pyrazoleox plays the role of acceptor in a reaction with the starting molecule via a N–N coupling and ring cleavage reaction of pyrazoles. The proposed reaction sequence consists of anodic oxidation, dimerization, rearrangement and reduction. The electrochemically catalyzed reactions were accomplished under constant-current and constant-potential conditions using an undivided electrochemical cell with the advantages of mild reaction conditions, remarkable yields and environmental compatibility.

Leveraging Pyrazolium Ylide Reactivity to Access Indolizine and 1,2‐Dihydropyrimidine Derivatives

“…N ‐Heterocyclic ylides are valuable precursors for synthetic heterocyclic chemistry. This is due to their accessibility and versatility in reactivity, capable of acting as nucleophiles, electrophiles, and 1,3‐dipoles [1–7] . Given the ubiquity of heterocycles as scaffolds for medicinal and materials chemistry, it is important to develop new methodologies that provide access to novel substitution patterns and increased structural diversity.…”