Allenes: Versatile Building Blocks in Cobalt-Catalyzed C-H Activation

The unique reactivity of allenes has led to their emergence as valuable coupling partners in transition-metal-mediated C-H activation reactions. On the other hand, due to its high abundance and high Lewis acidity, cobalt is garnering widespread interest as a useful catalyst for C-H activation. Here, we summarize cobalt-catalyzed C-H activations involving allenes as coupling partners and then describe our studies on Co(III)-catalyzed C-8 dienylation of quinoline N-oxides with allenes bearing a leaving group at the.-position for realizing a dienylation protocol.