A Highly Reactive Oxoiron(IV) Complex Supported by a Bioinspired N3O Macrocyclic Ligand

Inés Monte Pérez; Xenia Engelmann; Yong Min Lee; Mi Yoo; Elumalai Kumaran; Erik R. Farquhar; Eckhard Bill; Jason England; Wonwoo Nam; Marcel Swart; Kallol Ray

doi:10.1002/anie.201707872

A Highly Reactive Oxoiron(IV) Complex Supported by a Bioinspired N₃O Macrocyclic Ligand

Inés Monte Pérez, Xenia Engelmann, Yong Min Lee, Mi Yoo, Elumalai Kumaran, Erik R. Farquhar, Eckhard Bill, Jason England, Wonwoo Nam, Marcel Swart, Kallol Ray

Chemistry & Nanoscience

Research output: Contribution to journal › Article › peer-review

42 Scopus citations

Abstract

The sluggish oxidants [Fe^IV(O)(TMC)(CH₃CN)]²⁺ (TMC=1,4,8,11-tetramethyl-1,4,8,11-tetraazacyclotetradecane) and [Fe^IV(O)(TMCN-d₁₂)(OTf)]⁺ (TMCN-d₁₂=1,4,7,11-tetra(methyl-d₃)-1,4,7,11-tetraazacyclotetradecane) are transformed into the highly reactive oxidant [Fe^IV(O)(TMCO)(OTf)]⁺ (1; TMCO=4,8,12-trimethyl-1-oxa-4,8,12-triazacyclotetradecane) upon replacement of an NMe donor in the TMC and TMCN ligands by an O atom. A rate enhancement of five to six orders of magnitude in both H atom and O atom transfer reactions was observed upon oxygen incorporation into the macrocyclic ligand. This finding was explained in terms of the higher electrophilicity of the iron center and the higher availability of the more reactive S=2 state in 1. This rationalizes nature's preference for using O-rich ligand environments for the hydroxylation of strong C−H bonds in enzymatic reactions.

Original language	English
Pages (from-to)	14384-14388
Number of pages	5
Journal	Angewandte Chemie - International Edition
Volume	56
Issue number	46
DOIs	https://doi.org/10.1002/anie.201707872
State	Published - 13 Nov 2017

Bibliographical note

Funding Information:
Financial support from the DFG (Cluster of Excellence “Unifying Concepts in Catalysis”; EXC 314-2 to K.R.), MINECO (CTQ2014-59212-P and CTQ2015-70851-ERC to M.S.), GenCat (2014SGR1202 to M.S.), FEDER (UNGI10-4E-801 to M.S.), and COST action CM1305 “ECOSTBio” is gratefully acknowledged. K.R. also thanks the Heisenberg Program of the DFG for financial support. J.E. thanks the NTU for funding. W.N. and Y.-M.L. acknowledge financial support from the NRF of Korea through CRI (NRF-2012R1A3A2048842 to W.N.), GRL (NRF-2010-00353 to W.N.), and the Basic Science Research Program (2017R1D1A1B03029982 to Y.-M.L.). XAS experiments were conducted at the SSRL beamline 7-3 (SLAC National Accelerator Laboratory, USA), with support from the DOE Office of Science (DE-AC02-76SF00515) and the NIH (P30-EB-009998 and P41-GM-103393).

Publisher Copyright:
© 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Keywords

O ligands
hydrogen atom transfer
oxoiron(IV) complexes
oxygen atom transfer
spin state

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10.1002/anie.201707872

Cite this

@article{749a9e9cddf046438a6d1da06173fcd2,

title = "A Highly Reactive Oxoiron(IV) Complex Supported by a Bioinspired N3O Macrocyclic Ligand",

abstract = "The sluggish oxidants [FeIV(O)(TMC)(CH3CN)]2+ (TMC=1,4,8,11-tetramethyl-1,4,8,11-tetraazacyclotetradecane) and [FeIV(O)(TMCN-d12)(OTf)]+ (TMCN-d12=1,4,7,11-tetra(methyl-d3)-1,4,7,11-tetraazacyclotetradecane) are transformed into the highly reactive oxidant [FeIV(O)(TMCO)(OTf)]+ (1; TMCO=4,8,12-trimethyl-1-oxa-4,8,12-triazacyclotetradecane) upon replacement of an NMe donor in the TMC and TMCN ligands by an O atom. A rate enhancement of five to six orders of magnitude in both H atom and O atom transfer reactions was observed upon oxygen incorporation into the macrocyclic ligand. This finding was explained in terms of the higher electrophilicity of the iron center and the higher availability of the more reactive S=2 state in 1. This rationalizes nature's preference for using O-rich ligand environments for the hydroxylation of strong C−H bonds in enzymatic reactions.",

keywords = "O ligands, hydrogen atom transfer, oxoiron(IV) complexes, oxygen atom transfer, spin state",

author = "{Monte P{\'e}rez}, In{\'e}s and Xenia Engelmann and Lee, {Yong Min} and Mi Yoo and Elumalai Kumaran and Farquhar, {Erik R.} and Eckhard Bill and Jason England and Wonwoo Nam and Marcel Swart and Kallol Ray",

note = "Funding Information: Financial support from the DFG (Cluster of Excellence “Unifying Concepts in Catalysis”; EXC 314-2 to K.R.), MINECO (CTQ2014-59212-P and CTQ2015-70851-ERC to M.S.), GenCat (2014SGR1202 to M.S.), FEDER (UNGI10-4E-801 to M.S.), and COST action CM1305 “ECOSTBio” is gratefully acknowledged. K.R. also thanks the Heisenberg Program of the DFG for financial support. J.E. thanks the NTU for funding. W.N. and Y.-M.L. acknowledge financial support from the NRF of Korea through CRI (NRF-2012R1A3A2048842 to W.N.), GRL (NRF-2010-00353 to W.N.), and the Basic Science Research Program (2017R1D1A1B03029982 to Y.-M.L.). XAS experiments were conducted at the SSRL beamline 7-3 (SLAC National Accelerator Laboratory, USA), with support from the DOE Office of Science (DE-AC02-76SF00515) and the NIH (P30-EB-009998 and P41-GM-103393). Publisher Copyright: {\textcopyright} 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.",

year = "2017",

month = nov,

day = "13",

doi = "10.1002/anie.201707872",

language = "English",

volume = "56",

pages = "14384--14388",

journal = "Angewandte Chemie - International Edition",

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publisher = "John Wiley and Sons Ltd",

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TY - JOUR

T1 - A Highly Reactive Oxoiron(IV) Complex Supported by a Bioinspired N3O Macrocyclic Ligand

AU - Monte Pérez, Inés

AU - Engelmann, Xenia

AU - Lee, Yong Min

AU - Yoo, Mi

AU - Kumaran, Elumalai

AU - Farquhar, Erik R.

AU - Bill, Eckhard

AU - England, Jason

AU - Nam, Wonwoo

AU - Swart, Marcel

AU - Ray, Kallol

N1 - Funding Information: Financial support from the DFG (Cluster of Excellence “Unifying Concepts in Catalysis”; EXC 314-2 to K.R.), MINECO (CTQ2014-59212-P and CTQ2015-70851-ERC to M.S.), GenCat (2014SGR1202 to M.S.), FEDER (UNGI10-4E-801 to M.S.), and COST action CM1305 “ECOSTBio” is gratefully acknowledged. K.R. also thanks the Heisenberg Program of the DFG for financial support. J.E. thanks the NTU for funding. W.N. and Y.-M.L. acknowledge financial support from the NRF of Korea through CRI (NRF-2012R1A3A2048842 to W.N.), GRL (NRF-2010-00353 to W.N.), and the Basic Science Research Program (2017R1D1A1B03029982 to Y.-M.L.). XAS experiments were conducted at the SSRL beamline 7-3 (SLAC National Accelerator Laboratory, USA), with support from the DOE Office of Science (DE-AC02-76SF00515) and the NIH (P30-EB-009998 and P41-GM-103393). Publisher Copyright: © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

PY - 2017/11/13

Y1 - 2017/11/13

N2 - The sluggish oxidants [FeIV(O)(TMC)(CH3CN)]2+ (TMC=1,4,8,11-tetramethyl-1,4,8,11-tetraazacyclotetradecane) and [FeIV(O)(TMCN-d12)(OTf)]+ (TMCN-d12=1,4,7,11-tetra(methyl-d3)-1,4,7,11-tetraazacyclotetradecane) are transformed into the highly reactive oxidant [FeIV(O)(TMCO)(OTf)]+ (1; TMCO=4,8,12-trimethyl-1-oxa-4,8,12-triazacyclotetradecane) upon replacement of an NMe donor in the TMC and TMCN ligands by an O atom. A rate enhancement of five to six orders of magnitude in both H atom and O atom transfer reactions was observed upon oxygen incorporation into the macrocyclic ligand. This finding was explained in terms of the higher electrophilicity of the iron center and the higher availability of the more reactive S=2 state in 1. This rationalizes nature's preference for using O-rich ligand environments for the hydroxylation of strong C−H bonds in enzymatic reactions.

AB - The sluggish oxidants [FeIV(O)(TMC)(CH3CN)]2+ (TMC=1,4,8,11-tetramethyl-1,4,8,11-tetraazacyclotetradecane) and [FeIV(O)(TMCN-d12)(OTf)]+ (TMCN-d12=1,4,7,11-tetra(methyl-d3)-1,4,7,11-tetraazacyclotetradecane) are transformed into the highly reactive oxidant [FeIV(O)(TMCO)(OTf)]+ (1; TMCO=4,8,12-trimethyl-1-oxa-4,8,12-triazacyclotetradecane) upon replacement of an NMe donor in the TMC and TMCN ligands by an O atom. A rate enhancement of five to six orders of magnitude in both H atom and O atom transfer reactions was observed upon oxygen incorporation into the macrocyclic ligand. This finding was explained in terms of the higher electrophilicity of the iron center and the higher availability of the more reactive S=2 state in 1. This rationalizes nature's preference for using O-rich ligand environments for the hydroxylation of strong C−H bonds in enzymatic reactions.

KW - O ligands

KW - hydrogen atom transfer

KW - oxoiron(IV) complexes

KW - oxygen atom transfer

KW - spin state

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U2 - 10.1002/anie.201707872

DO - 10.1002/anie.201707872

M3 - Article

C2 - 28945949

AN - SCOPUS:85031499656

SN - 1433-7851

VL - 56

SP - 14384

EP - 14388

JO - Angewandte Chemie - International Edition

JF - Angewandte Chemie - International Edition

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