Brønsted Acid‐Catalyzed Intramolecular 7‐endo Hydroarylation Reaction of 1,5‐Diaryl‐1‐pentynes

Abstract A Brønsted acid‐catalyzed, transition metal‐free intramolecular 7‐ endo hydroarylation reaction of 1,5‐diaryl‐1‐pentynes has been developed. The use of 1,1,1,3,3,3‐hexafluoro‐2‐propanol (HFIP) as a solvent was found to be critical for this process. Using the present methodology, we have accomplished the synthesis of KGP‐18, an analogue of the anticancer natural product combretastatin A4. magnified image