Oxygen Atom Insertion into Iron(II) Phenyl and Methyl Bonds: A Key Step for Catalytic Hydrocarbon Functionalization

Oxy-functionalization
of metal–alkyl and −aryl bonds is a key step in potential
hydrocarbon oxidation catalysis. However, well-defined examples of
M–R to ROH conversion are rare, especially for first-row transition
metals. Cp*Fe­(CO)­(NCMe)­Ph reacts with oxygen or hydrogen peroxide
to produce benzoic acid. Removing CO from the Cp*Fe­(L)­(L′)­Ph
framework allows simple oxygen atom insertion into the Fe–Ph
bond. Cp*Fe­(P­(OCH2)3CEt)2Ph reacts
with Me3NO in THF to produce PhOH in high yield when Brønsted
acids are added. Studies show that light promotes P­(OCH2)3CEt dissociation from Cp*Fe­(P­(OCH2)3CEt)2Ph, which facilitates the conversion to PhOH. The
methyl analogue Cp*Fe­[P­(OCH2)3CEt]2Me reacts with oxidants to produce MeOH.