Pyrrole N–H anion complexes

Abstract

Synthetic pyrrole-based anion receptors date back to the 1990s. They have been extensively developed in the context of macrocyclic systems as expanded porphyrins and calixpyrroles, and related systems. The chemistry of open-chain pyrrolic systems is, in many respects, no less venerable. It also has more direct analogy to naturally occurring pyrrole-based anion binding motifs. However, it has not been the subject of a comprehensive review. Presented herein is a summary of efforts devoted to the creation of de novo pyrrole-based receptors, as well as the anion recognition chemistry of naturally occurring pyrrolic systems as prodigiosins and their synthetic analogues.

Supramolecular Chemistry of Anionic Dimers, Trimers, Tetramers, and Clusters

“…Non-conjugated pyrrole-containing macrocycles are another class of important anion receptors. 90 A number have been found to support complexes containing concurrently more than two anions. For instance, Guchhait et al 91 described the synthesis and structural characterization of several polyanion complexes of the azacalix[2]dipyrrolylmethanes 64 and 65 .…”

New dimensions in calix[4]pyrrole: the land of opportunity in supramolecular chemistry

“…Due to their unique conformations, structural diversity, and molecular recognition properties, calix [4]pyrroles (C4Ps) have been studied as modern generation host receptors in the arena of supramolecular chemistry. [4][5][6][7][8][9][10][11][12][13] C4Ps are synthetic non-planar, non-aromatic tetrapyrrolic macrocyclic receptors capable of binding an array of anions as well as neutral substrates through N-H hydrogen bonding. From a chemical viewpoint, in recent years, C4Ps have been explored as catalysts in preparative organic chemistry 14 and also as vital precursors for the generation of important organic molecules such as calixpyridines and calixpyridinopyrroles.…”

Linear Neutral Receptors for Anions: Synthesis, Structure and Applications

“…eroaromatic platforms opened up the possibility of binding support by electron pairs (pyridine) or an additional hydrogen bond donor (pyrrole) to influence the phenomenon of anion-receptor interactions. 9 In this short review we will retrace the development of platforms suitable for the construction of effective anion receptors: from simple aromatic derivatives to heteropolyaromatic structures, from two-hydrogen-bond receptors to compounds with more complex binding sites. In order to analyze the role of the platforms themselves, we will strive to present results for derivatives containing similar aromatic moieties on their peripheries.…”