Blue-luminescent 5-(3-indolyl)oxazoles via microwave-assisted three-component coupling–cycloisomerization–Fischer indole synthesis

Abstract

Aryl-substituted 5-(3-indolyl)oxazoles are readily synthesized in a novel one-pot three-component synthesis consisting of a microwave assisted sequence of Sonogashira coupling, an acid-catalyzed cycloisomerization, and a concluding Fischer indole synthesis. All title compounds are intensely blue-luminescent with large Stokes shifts upon UV-irradiation. The experimental absorption spectra are rationalized by ZINDO-CI computations based upon DFT geometry optimization.