Coordination chemistry of 1,3,5-triazapentadienes

The methods of synthesis of 1,3,5-triazapentadienes (also known as imidoylamidines), as well as the preparation of their complexes, are reviewed. The former methods include mainly the Pinner, Ley and Muller syntheses, the ami nation of N-imidoylimidoates or of nitrites bearing strong electron-withdrawing groups, the desulfurizing amination of N-tiobenzoylbenzamidines and the reaction of perfluoro-5-aza-4-nonene with primary amines. The synthetic procedures for the complexes involve not only the coordination of a pre-formed 1,3,5-triazapentadiene but also the generation in situ of such a species, namely by condensation of amidines, by direct one-pot template synthesis from nitrites, by nucleophilic addition of amidines or related reagents to coordinated nitrites, by nucleophilic additions to dicyanamidate or hydrolytic conversion of triazines. (C) 2010 Elsevier B.V. All rights reserved.