TY - JOUR
T1 - A Porphyrin Iron(III) π-Dication Species and its Relevance in Catalyst Design for the Umpolung of Nucleophiles
AU - Engbers, Silène
AU - Guo, Yisong
AU - Klein, Johannes E.M.N.
N1 - Funding Information:
J. E. M. N. K. acknowledges funding from the Nederlandse Organisatie voor Wetenschappelijk Onderzoek (NWO ENW‐KLEIN grant). Y. G. acknowledge funding from the National Institutes of Health (NIH GM125924). We thank the Center for Information Technology of the University of Groningen for their support and providing access to the Peregrine high performance computing cluster. This work also used the Dutch national e‐infrastructure with the support of the SURF Cooperative using grant no. EINF‐3867. S. E. thanks Ruben Feringa for his help in building an electrochemical cell for low temperature cyclic voltammetry, Philipp M. Stein for the synthesis of additional (TDFPP)FeCl complex and preliminary data, Renze Sneep for his help with high resolution mass spectrometry, Pieter van de Meulen and Johan Kemmink for their help with H NMR spectroscopy. S. E. also thanks Prof. Isaac Garcia Bosch at Carnegie Mellon University for access to equipment in his laboratory. 2
Publisher Copyright:
© 2023 The Authors. Angewandte Chemie International Edition published by Wiley-VCH GmbH.
PY - 2023/11/13
Y1 - 2023/11/13
N2 - Isoporphyrins have recently been identified as remarkable species capable of turning the nucleophile attached to the porphyrin ring into an electrophile, thereby providing umpolung of reactivity (Inorg. Chem. 2022, 61, 8105–8111). They are generated by nucleophilic attack on an iron(III) π-dication, a class of species that has received scant attention. Here, we explore the effect of the porphyrin meso-substituent and report a iron(III) π-dication bearing the meso-tetraphenylporphyrin (TPP) ligand. We provide an extensive study of the species by UV/Vis absorption, 2H NMR, EPR, applied field Mössbauer, and resonance Raman spectroscopy. We further explore the system's highly dynamic and tunable properties and address the nature of the axial ligands as well as the conformation of the porphyrin ring. The insights presented are essential for the rational design of catalysts for the umpolung of nucleophiles. Such catalytic avenues could for example provide a novel method for electrophilic chlorinations. We further examine the importance of electronic tuning of the porphyrin by nature of the meso-substituent as a factor in catalyst design.
AB - Isoporphyrins have recently been identified as remarkable species capable of turning the nucleophile attached to the porphyrin ring into an electrophile, thereby providing umpolung of reactivity (Inorg. Chem. 2022, 61, 8105–8111). They are generated by nucleophilic attack on an iron(III) π-dication, a class of species that has received scant attention. Here, we explore the effect of the porphyrin meso-substituent and report a iron(III) π-dication bearing the meso-tetraphenylporphyrin (TPP) ligand. We provide an extensive study of the species by UV/Vis absorption, 2H NMR, EPR, applied field Mössbauer, and resonance Raman spectroscopy. We further explore the system's highly dynamic and tunable properties and address the nature of the axial ligands as well as the conformation of the porphyrin ring. The insights presented are essential for the rational design of catalysts for the umpolung of nucleophiles. Such catalytic avenues could for example provide a novel method for electrophilic chlorinations. We further examine the importance of electronic tuning of the porphyrin by nature of the meso-substituent as a factor in catalyst design.
KW - Bioinspired Reactivity
KW - Halogenation
KW - Isoporphyrins
KW - Umpolung
KW - π-Dication
UR - http://www.scopus.com/inward/record.url?scp=85173774342&partnerID=8YFLogxK
U2 - 10.1002/anie.202313006
DO - 10.1002/anie.202313006
M3 - Article
AN - SCOPUS:85173774342
SN - 1433-7851
VL - 62
JO - Angewandte Chemie - International Edition
JF - Angewandte Chemie - International Edition
IS - 46
M1 - e202313006
ER -