Diversity-oriented syntheses of functional π-systems by multicomponent and domino reactions

Functional π-electron systems can be synthesized in a diversity-oriented fashion by applying multicomponent and domino reactions. Based upon alkyne activation by Sonogashira coupling, reactive triple or double bonds become the key functionality for sequential and consecutive synthesis of heterocycles, such as β-amino vinyl nitrothiophenes, δ-amino propenylidene indolones, indolizines, furans, pyrroles, annelated 2-amino pyridines, and spirocyclic benzofuranones and indolones. All these chromophores and fluorophores possess peculiar properties such as nonlinear optical (NLO) activity, pH-sensitivity, distinct solid-state fluorescence, or large Stokes shifts.