Multicomponent reactions mediated by NbCl5 for the synthesis of phthalonitrile-quinoline dyads: Methodology, scope, mechanistic insights and applications in phthalocyanine synthesis

Abstract

Herein, we demonstrate the efficiency of NbCl5 to promote a multicomponent reaction (MCR) for the synthesis of a library of phthalonitrile-quinoline dyads, which are very useful and new functionalized building blocks for phthalocyanine (PC) synthesis. Experimental mechanistic insights on the key MCR process are described, using a deuterated reagent, clearly showing the pericyclic nature of a hetero-Diels-Alder reaction. Examples of phthalocyanine (PC) syntheses were performed in order to demonstrate the versatility of the phthalonitrile-quinoline dyads. Preliminary photophysical measurements show that our phthalonitrile library is very promising for the production of new molecular scaffolds of PC derivatives with potential applications.