Tunneling Controls the Reaction Pathway in the Deformylation of Aldehydes by a Nonheme Iron(III)-Hydroperoxo Complex: Hydrogen Atom Abstraction versus Nucleophilic Addition
- 주제(기타) Chemistry, Multidisciplinary
- 설명문(일반) [Bae, Seong Hee; Li, Xiao-Xi; Seo, Mi Sook; Lee, Yong-Min; Fukuzumi, Shunichi; Nam, Wonwoo] Ewha Womans Univ, Dept Chem & Nano Sci, Seoul 03760, South Korea; [Fukuzumi, Shunichi] Meijo Univ, Japan Sci & Technol Agcy JST, SENTAN, Fac Sci & Engn, Nagoya, Aichi 4688502, Japan; [Nam, Wonwoo] Chinese Acad Sci, LICP, Suzhou Res Inst, State Key Lab Oxo Synth & Select Oxidat, Lanzhou 730000, Gansu, Peoples R China
- 등재 SCIE, SCOPUS
- 발행기관 AMER CHEMICAL SOC
- 발행년도 2019
- URI http://www.dcollection.net/handler/ewha/000000159690
- 본문언어 영어
- Published As http://dx.doi.org/10.1021/jacs.9b02272
- PubMed https://pubmed.ncbi.nlm.nih.gov/31034219
초록/요약
Mononuclear nonheme iron(III)-hydroperoxo intermediates play key roles in biological oxidation reactions. In the present study, we report the highly intriguing reactivity of a nonheme iron(III)-hydroperoxo complex, [(TMC)Fe-III(OOH)(2+) (1), in the deformylation of aldehydes, such as 2-phenylpropionaldehyde (2-PPA) and its derivatives; that is, the reaction pathway of the aldehyde deformylation by 1 varies depending on reaction conditions, such as temperature and substrate. At temperature above 248 K, the aldehyde deformylation occurs predominantly via a nucleophilic addition (NA) pathway. However, as the reaction temperature is lowered, the reaction pathway changes to a hydrogen atom transfer (HAT) pathway. Interestingly, the reaction rate becomes independent of temperature below 233 K with a huge kinetic isotope effect (KIE) value of 93 at 203 K, suggesting that the HAT reaction results from tunneling. In contrast, reactions with a deuterated 2-PPA at the alpha-position and 2-methyl-2-phenylpropionaldehyde proceed exclusively via a NA pathway irrespective of the reaction temperature. We conclude that the bifurcation pathways between NA and HAT result from the tunneling effect in the HAT reaction by 1. To the best of our knowledge, this study reports the first example showing that tunneling plays a significant role in the activation of substrate C-H bonds by a mononuclear nonheme iron(III)-hydroperoxo complex.
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