Facile single-step synthesis of pentaaryl-substituted pyrano[3,2-b]pyrrol-5(1H)-ones showing aggregation-induced emission

Abstract

The continuing desire for multifunctional AIE materials has stimulated intensified research efforts to develop both innovative synthetic techniques and novel scaffolds. Herein, we report a new class of heterocyclic AIEgens, 1,2,3,6,7-pentaaryl substituted pyrano[3,2-b]pyrrol-5(1H)-ones, which contain an intriguing fused pyrrole/α-pyrone core. These structurally novel molecules were efficiently constructed via multicomponent reactions of easily accessible isatins, 2,3-diaryl cyclopropenones, and alkyl bromides in a single step under metal-free conditions. Subsequent late-stage modification of the resulting products was performed via the Suzuki–Miyaura coupling and reduction reactions. Furthermore, the HOMO/LUMO gaps were calculated and the single crystal structural analyses were conducted in order to gain deeper insights into the photophysical properties of these propeller-like AIEgens.