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C-H Activation from Iron(II)-Nitroxido Complexes.

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(?1 -TEMPO) and (Ar L)Fe(?2 -N,O-AZADO) (Ar L=1,9-(2,4,6-Ph3 C6 H2 )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(?1 -TEMPO) reacts to give a diferrous hydroxide [(Ar L)Fe]2 (?-OH)2 , the reaction of four-coordinate (Ar L)Fe(?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.

SUBMITTER: Kleinlein C

PROVIDER: S-EPMC5672810 | biostudies-literature | 2017 Sep

REPOSITORIES: biostudies-literature

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C-H Activation from Iron(II)-Nitroxido Complexes.

Kleinlein Claudia C Bendelsmith Andrew J AJ Zheng Shao-Liang SL Betley Theodore A TA

Angewandte Chemie (International ed. in English) 20170825 40

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(κ1 -TEMPO) and (Ar L)Fe(κ2 -N,O-AZADO) (Ar L=1,9-(2,4,6-Ph3 C6 H2 )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 t ...[more]

PMID: 28766325

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