Facile construction of 3-indolochromenes and 3-indoloxanthenes via EDDF catalyzed one-pot three component reactions

Abstract

A novel and green strategy for the construction of biologically relevant 3-indolochromene and 3-indoloxanthene scaffolds is reported using EDDF as a catalyst and ethylene glycol as a promoter solvent. The catalytic system offers wider applicability, crossing over a variety of substrates, besides affording exclusively the desired product in shorter reaction times and high yields. Furthermore, the ease of work-up and purification combined with the recyclability of the EDDF–ethylene glycol system makes the present method environmentally sustainable and amenable to large-scale synthesis as well.