Bronsted Acid-Catalyzed Intramolecular 7-endo Hydroarylation Reaction of 1,5-Diaryl-1-pentynes

A Bronsted 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.

Automated summary

A Bronsted 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.