Mannich Reaction: An Alternative Synthetic Approach for Various Pyrrole‐Based Anion Receptors and Chelating Ligands
Tapas Guchhait, Satabdi Roy, Priyadarshini Jena
Abstract
Abstract This review article highlights the synthetic design of various pyrrole‐based acyclic, tripodal, macrocyclic, and macrobicyclic Mannich bases and their applications, mainly as anion receptors. By varying the amine‐types and molar proportions of reagents, a range of value‐added Mannich bases are obtained. Herein, the synthesis and properties of several azacalixpyrroles, azacalixdipyrrolylmethanes, and azacryptands are discussed. Emphasis is also given to the applications of pyrrole‐based Mannich bases in the construction of some chelating ligands as one of the steps in multistep organic syntheses. In addition, the use of Mannich products as ligands for synthesizing metal complexes is also described. More importantly, the establishment of Mannich reactions as an alternative approach for traditionally used Schiff's base or aldehyde/ketone‐condensation reactions is delineated.