Non‐Covalent Interaction‐Controlled Site‐Selective C−H Transformations

Abstract

Site‐selective C−H transformations are important to obtain desired compounds as single products in a highly efficient manner. However, it is generally difficult to achieve such transformations because organic substrates contain many C−H bonds with similar reactivities. Therefore, the development of practical and efficient methods for controlling site selectivity is highly desirable. The most frequently used strategy is “directing group method”. Although this method is highly effective and promotes site‐selective reactions, it has several limitations. Our group recently reported other methods to achieve site‐selective C−H transformations using non‐covalent interactions between a substrate and a reagent or a catalyst and a substrate (non‐covalent method). In this personal account, the background of site‐selective C−H transformations, our reaction design to achieve site‐selective C−H transformations, and recently reported reactions are explained.

Boronyl-Group-Assisted Decatungstate-Catalyzed Benzylic C(sp3)–H Alkylation

“…We recently developed the C­(sp 3 )–H alkylation of ammonium salts using the decatungstate photocatalyst, [W 10 O 32 ] 4– (Scheme A). − In these reactions, electrostatic interactions between the cationic ammonium group (−NH 3 + ) and the anionic [W 10 O 32 ] 4– play a key role. We envisioned that electron-rich [W 10 O 32 ] 4– could function as a hydrogen bond acceptor and interact with a boronyl group, which could function as a hydrogen bond donor.…”