Porous Organic Polymer-Derived Nanopalladium Catalysts for Chemoselective Synthesis of Antitumor Benzofuro[2,3-b]pyrazine from 2-Bromophenol and Isonitriles

An efficient strategy for the synthesis of benzofuro[2,3- b]pyrazines was developed. These tricyclic scaffolds were formed through a multistep cascade sequence, which includes double insertion of isonitriles and chemoselective bicyclization. In this reaction, a nanopalladium was used as a recyclable catalyst. Product 3w exhibited excellent anticancer activity toward T-24 (IC50 = 12.5 ± 0.9 μM) and HeLa (IC50 = 14.7 ± 1.6 μM) cells. We also explored the action mechanism of 3w on T-24 cells.