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.

Keywords:

• 9-phenanthrol
• Suzuki reaction
• intramolecular
• Friedel-Crafts reaction
• cytotoxic activity

Additional information

Funding

Financial support for this work from the National Key R&D Program (Grant No. 2018YFD0200105), and the National Natural Science Foundation of China (Grant No. 21572060), and the Shanghai Key Laboratory of Catalysis Technology for Polyolefins (LCTP-201301) is gratefully acknowledged.