Direct Electrophilic C−H Alkynylation of Unprotected 2‐Vinylanilines

Unprotected aromatic amines can be used as directing groups in metal‐catalyzed C−H alkynylations of alkenes. By using low amounts of an Ir III catalyst in combination with alkynylbenziodoxolones as electrophilic alkyne‐transfer reagents, highly desirable 1,3‐enynes were isolated in excellent yields of up to 98 % with Z stereoselectivity. A broad substrate scope as well as the high synthetic utility of the 1,3‐enynes render this new method an efficient approach for the synthesis of five‐ and six‐membered heterocycles. Further derivatizations of the 1,3‐enynes to highly substituted quinolines through Au I ‐ and N ‐bromosuccinimide‐mediated exo‐dig cyclizations were demonstrated.