Visible-Light-Driven Intermolecular Reductive Ene-Yne Coupling by Iridium/Cobalt Dual Catalysis for C(sp3)-C(sp2) Bond Formation

A new methodology to form C(sp(3))-C(sp(2)) bonds by visible-light-driven intermolecular reductive ene-yne coupling has been successfully developed. The process relies on the ability of the Hantzsch ester to contribute in both SET and HAT processes through a unified cobalt and iridium catalytic system. This procedure avoids the use of stoichiometric amounts of reducing metallic reagents, which is translated into high functional-group tolerance and atom economy.