Expanding the Scope of Alkynes in C-H Activation: Weak Chelation-Assisted Cobalt-Catalyzed Synthesis of Indole C(4)-Acrylophenone C-O Bond Cleavage of Propargylic Ethers.

Herein, we report the facile synthesis of indole C(4)-acrylophenone using a C-H bond activation strategy. For this conversion, an unsymmetrical alkyne (phenylethynyl ether) in the presence of cobalt(III)-catalyst works efficiently. In this process, alkyne gets oxidized in the presence of generated water, which is the key step for this method, for which trifluoroethanol is the water source.

Weak-Chelation Assisted Cobalt-Catalyzed C-H Bond Activation: An Approach Toward Regioselective Ethynylation of -Aryl γ-Lactam.

The sustainable C-H bond ethynylation of -aryl γ-lactam has been achieved in a highly regioselective manner. In this protocol, earth-abundant cobalt(III)-catalyst was found to be effective, triggering the C-H metalation using a weakly coordinating lactam group. Herein, the ortho-()-H ethynylation has been obtained regioselectively.