TY - JOUR
T1 - A Mn II Mn III -Peroxide Complex Capable of Aldehyde Deformylation
AU - Magherusan, Adriana M.
AU - Kal, Subhasree
AU - Nelis, Daniel N.
AU - Doyle, Lorna M.
AU - Farquhar, Erik R.
AU - Que, Lawrence
AU - McDonald, Aidan R.
N1 - Publisher Copyright:
© 2019 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
PY - 2019/4/16
Y1 - 2019/4/16
N2 - Ribonucleotide reductases (RNRs) are essential enzymes required for DNA synthesis. In class Ib Mn 2 RNRs superoxide (O 2 .− ) was postulated to react with the Mn II 2 core to yield a Mn II Mn III -peroxide moiety. The reactivity of complex 1 ([Mn II 2 (O 2 CCH 3 ) 2 (BPMP)](ClO 4 ), where HBPMP=2,6-bis{[(bis(2-pyridylmethyl)amino]methyl}-4-methylphenol) towards O 2 .− was investigated at −90 °C, generating a metastable species, 2. The electronic absorption spectrum of 2 displayed features (λ max =440, 590 nm) characteristic of a Mn II Mn III -peroxide species, representing just the second example of such. Electron paramagnetic resonance and X-ray absorption spectroscopies, and mass spectrometry supported the formulation of 2 as a Mn II Mn III -peroxide complex. Unlike all other previously reported Mn 2 -peroxides, which were unreactive, 2 proved to be a capable oxidant in aldehyde deformylation. Our studies provide insight into the mechanism of O 2 -activation in Class Ib Mn 2 RNRs, and the highly reactive intermediates in their catalytic cycle.
AB - Ribonucleotide reductases (RNRs) are essential enzymes required for DNA synthesis. In class Ib Mn 2 RNRs superoxide (O 2 .− ) was postulated to react with the Mn II 2 core to yield a Mn II Mn III -peroxide moiety. The reactivity of complex 1 ([Mn II 2 (O 2 CCH 3 ) 2 (BPMP)](ClO 4 ), where HBPMP=2,6-bis{[(bis(2-pyridylmethyl)amino]methyl}-4-methylphenol) towards O 2 .− was investigated at −90 °C, generating a metastable species, 2. The electronic absorption spectrum of 2 displayed features (λ max =440, 590 nm) characteristic of a Mn II Mn III -peroxide species, representing just the second example of such. Electron paramagnetic resonance and X-ray absorption spectroscopies, and mass spectrometry supported the formulation of 2 as a Mn II Mn III -peroxide complex. Unlike all other previously reported Mn 2 -peroxides, which were unreactive, 2 proved to be a capable oxidant in aldehyde deformylation. Our studies provide insight into the mechanism of O 2 -activation in Class Ib Mn 2 RNRs, and the highly reactive intermediates in their catalytic cycle.
KW - Mn Mn -peroxide
KW - aldehyde deformylation
KW - nucleophilic reactivity
KW - ribonucleotide reductases
KW - superoxide activation
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U2 - 10.1002/anie.201900717
DO - 10.1002/anie.201900717
M3 - Article
C2 - 30830996
AN - SCOPUS:85063572902
SN - 1433-7851
VL - 58
SP - 5718
EP - 5722
JO - Angewandte Chemie - International Edition
JF - Angewandte Chemie - International Edition
IS - 17
ER -