Efficient Palladium‐Catalyzed Aerobic Arylative Carbocyclization of Enallenynes

Herein, we communicate a selective and efficient protocol for oxidative arylating carbocyclization of enallenynes using O(2) as the oxidant. The key to success for this aerobic transformation is the application of a specific electron transfer mediator (ETM), a bifunctional catalyst consisting of a metal‐macrocycle and quinone moieties. This catalyst significantly facilitates the reoxidation of Pd(0) to Pd(II) under atmospheric pressure of O(2). Diverse functionalized enallenynes react with aryl boronic acids to afford the corresponding cyclic tetraenes in moderate to good yields.