Ethers as Building Blocks for the Synthesis and Modification of N‐Heterocycles

The use of C‐H compounds as reactive partners in a variety of transformations represents the state of the art in synthetic methodology. In this review, we have summarized the main achievements in using ethers as building blocks for the construction and modification of one of the basic platforms of organic chemistry, nitrogen‐containing heterocycles. Ethers, previously considered mainly as solvents, are excellent CH‐partners, capable of generating radical or cationic reactive species under the action of HAT agents and oxidants. The challenge in this field is the still limited number of heterocyclic systems and other starting reagents, with which the processes can be carried out selectively due to closer bond dissociation energies and oxidation potentials of heterocycles, reactive intermediates and ethers. However, the fine‐tuning of the reaction system using electro‐ and photochemical approaches and a deep understanding of the reaction pathways make the use of ethers as C‐H reagents a promising synthetic strategy.