Figure 18.
Fe(PDP) discriminates between aliphatic C–H bonds on the basis of their stereoelectronic properties. (A) Oxygen functionality hyperconjugatively activates adjacent methylene sites to furnish preparative yields of mono-oxidized products with Fe(PDP) oxidations and light-promoted radical xanthylation. (B,C) Cyclopropane rings that act as hyperconjugative activators in Fe(PDP) catalysis are opened with radical reagents. (D) Ring-strain release (release of torsional strain) promotes oxidation at C3 of substituted cyclohexane rings with Fe(PDP) catalysis.