Halogen‐Bond‐Promoted α‐C−H Amination of Ethers for the Synthesis of Hemiaminal Ethers

A simple halogen‐bond‐promoted α‐C−H amination of ether/thioether with a variety of N−H compounds has been accomplished. In the presence of low‐cost and readily available perfluorobutyl iodide, a diverse range of hemiaminal ether derivatives, including the valuable hydrazone hemiaminal ethers, were quickly assembled under thermal or visible‐light irradiation conditions. Mechanistic studies suggest that a halogen‐bond adduct was formed and a radical chain pathway might be operative. Synthetic application of the method has been demonstrated via the preparation of the anti‐viral and anti‐tumor drug, Tegafur. magnified image