Iodine(III)-mediated oxidative intramolecular arene-alkene coupling exemplified in the synthesis of phenanthrenes

Abstract

An iodine(III)-mediated synthesis of substituted phenanthrenes from ortho-vinylated biaryl derivatives through highly 6-endo-trig selective oxidative intramolecular arene-alkene coupling is reported. The title method allows for the construction of diversely functionalized target compounds under very mild conditions and in yields ranging up to 79%. Preliminary mechanistic investigations indicate that the reaction presumably proceeds via activation of the alkene moiety followed by a Friedel-Crafts-type electrophilic aromatic substitution at the adjacent arene ring.