Site-Selective C-H Functionalization by Decatungstate Anion Photocatalysis: Synergistic Control by Polar and Steric Effects Expands the Reaction Scope

The synergistic control of the S_H2 transition states of hydrogen abstraction by polar and steric effects provides a promising strategy in achieving site-selective C(sp³)-H functionalization under decatungstate anion photocatalysis. By using this photocatalytic approach, the C-H bonds of alkanes, alcohols, ethers, ketones, amides, esters, nitriles, and pyridylalkanes were functionalized site-selectively. In the remarkable case of a 2,4-disubstituted cyclohexanone bearing five methyl, five methylene, and three methine C-H bonds, one methine C-H bond in the isoamyl tether was selectively functionalized.