Brønsted Acid-Promoted One-Pot Synthesis of Chrysene Derivatives via Isochromenylium Intermediate Formed in Situ

Trifluoromethanesulfonic acid (HOTf) promoted cross-coupling of <i>ortho</i>-[2-(4-methoxylphenyl)-alkynyl]­acetophenones with <i>ortho</i>-alkynylbenzaldehydes affording chrysene derivatives has been developed. The present cascade reaction provides a facile one-pot synthesis of multisubstituted chrysenes as well as naked chrysene under mild conditions. The mechanism experimental results demonstrate isochromenylium is a key intermediate for this transformation