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.

The catalytic decarbonylation reaction of aliphatic carboxylic acids can be carried out in the presence of an iron complex, and it proceeds smoothly to give α-olefins with high selectivity.