Tropylium Tetrafluoroborate Catalyzed 1,6-Conjugate Addition of Indoles to p-Quinone Methides

Abstract

Tropylium tetrafluoroboratehas been utilized as a BrØnsted base for the 1,6-conjugate addition of indoles to para-quinone methides. This transformation occurs at mild conditions and is tolerant to a variety of functional groups. This protocol provides an easy and straightforward access to a set of unsymmetrical diarylindolylmethanes in good to excellent yield.