Bimetallic Iron-Palladium Catalyst System as a Lewis-Acid for the Synthesis of Novel Pharmacophores Based Indole Scaffold as Anticancer Agents.

The Friedel-Crafts reaction between substituted indoles as nucleophiles with chalcones-based benzofuran and benzothiophene scaffolds was carried out by employing a highly efficient bimetallic iron-palladium catalyst system. This catalytic approach produced the desired -heteroaryl products with low catalyst loading, a simple procedure, and with acceptable yield. All synthesized indole scaffolds - were initially evaluated for their cytotoxic effect against human fibroblast BJ cell lines and appeared to be non-cytotoxic. All non-cytotoxic compounds - were then evaluated for their anticancer activities against cervical cancer HeLa, prostate cancer PC3, and breast cancer MCF-7 cell lines, in comparison to standard drug doxorubicin, with IC values 1.9 ± 0.4 µM, 0.9 ± 0.14 µM and 0.79 ± 0.05 µM, respectively, and appeared to be moderate to weak anticancer agents. Fluoro-substituted chalcone moiety-containing compounds, appeared to be the most active member of the series against cervical HeLa (IC = 8.2 ± 0.2 µM) and breast MCF-7 cancer cell line (IC = 12.3 ± 0.04 µM), whereas 6-fluroindol-4-bromophenyl chalcone-containing compound (IC = 7.8 ± 0.4 µM) appeared to be more active against PC3 prostate cancer cell line.