Copper-Mediated Cascade Trifunctionalization of N-Propargylamides

The trifunctionalization of alkynes accompanied by intramolecular migration is one of the most powerful tools for rapid enhancing of molecular complexity in synthetic chemistry. Despite significant achievements have been made in the presence of noble metals (such as Au-, Rh-, Pd-, etc.), employment of copper is still underrepresented. Furthermore, 1,1-diiodoalkenes is the core structure of varieties natural products and pharmaceuticals, as well as valuable intermediates for futher manipulations. Herein we report a general and step-economic protocol for the synthesis of 1,1-diiodoalkenes via copper-mediated cascade trifunctionalization of N-propargylamides with halogen sources and tert-butyl nitrite (TBN). This three-component trifunctionalization method enables one-step formation of six new chemical bonds in a high chemo- and regioselective manner. Moreover, the synthesized products have also been selected for evaluation of antitumor activities. One compound was found to display the best potent inhibitory activities against A549, SMMC-7721 and T-24 cells with IC50 values of 9.16, 23.83 and 18.13 mu mol L-1.