Directed C−H Allylation of Aromatic Carboxamides with Allyl Aryl Ethers under CpCo(III)‐Catalysis

The Cp*Co(III) C−H allylation of (hetero)arenes with allyl aryl ethers has been developed using an amide as directing group (24 examples). DFT calculations have shed light on the mechanistic course and reactivity pattern, showing that strong electron releasing groups favour the reaction by reducing the activation barrier of the rate‐determining C−H activation step. However, the steric strain can increase the energy of the migratory insertion step to the point of completely preventing the reaction, as in the case of the 3,5‐dimethylbenzamide. The obtained allylated compounds have been transformed into a variety of interesting heterocyclic and carbocyclic structures, such as isoquinolones and isochromanones. Allyl aryl ethers have proved to be efficient allylating agents for (hetero)arenes under Cp*Co(III) catalysis using an amide as directing group. DFT calculations have shed light on the mechanistic course and reactivity pattern.