Synthesis of 9-Phenanthrols through a Sequential Ligand-Free Suzuki/Intramolecular Friedel-Crafts Reaction and Their Cytotoxic Activity

Abstract

A facile and efficient approach for the synthesis of 9-phenanthrols through a sequential ligand-free Suzuki/intramolecular Friedel-Crafts reaction has been developed. Twenty-five 2-([1,1′-biphenyl]-2-yl)acetic acids were obtained via Suzuki reaction with high yields. And 9-phenanthrols were regioselectively synthesized by TfOH/P2O5 catalyzed intramolecular Friedel-Crafts reaction with good to excellent yields. This method provides a valuable alternative to the existing strategies toward the synthesis of 9-phenanthrols. Furthermore, cytotoxic activity test indicated that the synthesized 9-phenanthrols could inhibit viability of HepG2 cells in a dose-dependent way. Ten compounds displayed over 70% inhibition proportions after 24 h at the concentration of 100 μM.