Electrochemical Cascade Cyclization of N‐Centered Radicals with Electro‐Deficient Alkynes

Indoline‐fused polycyclic scaffolds are virtually universal in biological and pharmaceutical. Here we demonstrate a facile electrooxidative cascade cyclization for indoline‐based derivatives, employing amidyl radicals with ynones under mild conditions. The efficient method enables the formation of two new C−N and C−C bonds in a single step with high regioselectivity. Various indoline‐based tetracyclic 6/5/6/6 skeletons can be achieved through a biscyclization/dehydrogenation cascade process. Additionally, this electrochemical strategy proceeds in a sustainable metal‐ and oxidant‐free condition, with H2 being the solely byproduct. An electrochemcial synthesis of indoline‐fused polycycles by constructing both the five‐ and six‐membered heterocyclic rings in a single step from arylamide‐tethered ynones has been developed, which provides facile access to various indoline‐based tetracyclic 6/5/6/6 skeletons with highly regioselective control in a sustainable, metal‐ and oxidant‐free condition.