Pyrrole derivatives are nitrogen-containing heterocyclic compounds and widely
distributed in a large number of natural and non-natural compounds. These compounds
possess a broad spectrum of biological activities such as anti-infammatory, antiviral, antitumor,
antifungal, and antibacterial activities. Besides their biological activity, pyrrole derivatives
have also been applied in various areas such as dyes, conducting polymers, organic
semiconductors.
Due to such a wide range of applicability, access to this class of compounds has attracted
intensive research interest. Various established synthetic methods such as Paal-Knorr,
Huisgen, and Hantzsch have been modified and improved. In addition, numerous novel
methods for pyrrole synthesis have been discovered. This review will focus on considerable
studies on the synthesis of pyrroles, which date back from 2014.