FeCl3-catalyzed dimerization/elimination of 1,1-diarylalkenes: efficient synthesis of functionalized 4H-chromenes

Org Biomol Chem. 2018 Jan 31;16(5):703-706. doi: 10.1039/c7ob02941a.

Abstract

An efficient synthesis of valuable poly-substituted 4H-chromenes was developed via a [4 + 2] cycloaddition followed by the elimination of 1,1-diarylalkenes. The inexpensive FeCl3 salt has proven to be an efficient catalyst for this transformation. The commercial availability of the catalyst and reagents, together with a convenient procedure, makes this an attractive method for 4H-chromene synthesis.