Amidines: their synthesis, reactivity, and applications in heterocyclic synthesis

Abstract

The reactivity of amidines makes them valuable as building blocks for the synthesis of heterocyclic motifs of biological relevance, for functional materials, for organo-catalysts and as ligand in metal-complexes. As a large number of publications have recently reported on the reactivity of amidines, we compiled some features of these interesting molecules. Consequently, this article aims to review the preparation of functionalized amidines and to highlight their use as starting materials in the synthesis of various organic molecule classes, especially heterocyclic structures. In this review, we cover also related name reactions such as the Pinner reaction.

From cyclic amines and acetonitrile to amidine zinc(ii) complexes

“…25 Owing to their reactivity, amidines are valuable precursors in the synthesis of heterocyclic compounds and as catalysts. 26 Our study aimed to uncover the role of zinc(II) in the formation of amidines.…”

Synthesis of Boronated Amidines by Addition of Amines to Nitrilium Derivative of Cobalt Bis(Dicarbollide)

“…In contrast to the primary amines, the nucleophilic addition of secondary amines (dimethylamine, diethylamine, piperidine and morpholine) to the activated triple bond of [8-EtC≡N-3,3 -Co(1,2-C 2 B 9 H 10 )(1 ,2 -C 2 B 9 H 11 )] results in the formation of exclusively E isomers of amidines 7-10 (Scheme 2). The formation of only E isomers was previously observed for the nucleophilic addition of secondary amines to the propionitrilium derivative of nido-carborane, whereas the reactions with primary amines resulted in mixtures of E and Z isomers [56].…”

“…Amidines, that are the nitrogen analogues of carboxylic acids and esters, are well known and studied class of organic compounds [52][53][54][55][56]. Amidine derivatives are commonly used for the synthesis of many important heterocycles such as imidazoles, triazoles, thiazoles, oxadiazoles, pyrimidines, pyridines and triazines.…”

Rapid and efficient synthesis of formamidines in a catalyst-free and solvent-free system

“…Amidines are ubiquitous in nature and have critical roles in pharmaceutical and agrochemical industries. 1 In addition, amidine derivatives have been documented as key scaffolds in drug discovery 2 and crucial fragments in numerous biologically relevant molecules. 3 As a unique class of amidines, N -sulfonyl formamidines are widespread in insecticidal/acaricidal drugs 4 or biologically active molecules.…”