Strategies and Methods for the Synthesis of 2‐Pyrazolines: Recent Developments (2012–2022)

Abstract

Abstract2‐Pyrazolines are important five‐membered heterocycles, containing two adjacent nitrogen atoms. They can incorporate various functional groups and possess unique biological properties. Moreover, they have been used as useful building blocks. In recent years, the field of 2‐pyrazoline synthesis has experienced enormous progress. Novel strategies have been developed, and many studies reporting improvements or adaptations of existing protocols have been published, giving access to new functionalizations, unexplored structures, and/or enantioselective synthesis. This review summarizes the progress made in synthetic methodologies during the period from 2012 to 2022. The functionalization challenges and capabilities, scopes and limitations of the reactions, substitution patterns, and mechanisms of the reactions, where appropriate, will be discussed.