C−H Activation from Iron(II)‐Nitroxido Complexes
Year: 2017
Type: article
Abstract: The reaction of nitroxyl radicals TEMPO (2,2′,6,6′‐tetramethylpiperidinyloxyl) and AZADO (2‐azaadamantane‐N‐oxyl) with an iron(I) synthon affords iron(II)‐nitroxido complexes ( Ar L)Fe(κ 1 ‐TEMPO) and ( Ar L)Fe(κ 2 ‐N,O‐AZADO) ( Ar L=1,9‐(2,4,6‐Ph 3 C 6 H 2 ) 2 ‐5‐mesityldipyrromethene). Both high‐spin iron(II)‐nitroxido species are stable in the absence of weak C−H bonds, but decay via N−O bond homolysis to ferrous or ferric iron hydroxides in the presence of 1,4‐cyclohexadiene. Whereas ( Ar L)Fe(κ 1 ‐TEMPO) reacts to give a diferrous hydroxide [( Ar L)Fe] 2 (μ‐OH) 2 , the reaction of four‐coordinate ( Ar L)Fe(κ 2 ‐N,O‐AZADO) with hydrogen atom donors yields ferric hydroxide ( Ar L)Fe(OH)(AZAD). Mechanistic experiments reveal saturation behavior in C−H substrate and are consistent with rate‐determining hydrogen atom transfer.
Institution: Harvard University
Language: English
Subfield: Inorganic Chemistry
Field: Chemistry
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W2742049577