Characterization of the structure and reactivity of monocopper-oxygen complexes supported by β-diketiminate and anilido-imine ligands
| Autor: | Benjamin F. Gherman, Christopher J. Cramer, William B. Tolman |
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| Rok vydání: | 2006 |
| Předmět: |
Models
Molecular Molecular Conformation chemistry.chemical_element Dopamine beta-Hydroxylase Ligands Medicinal chemistry Oxygen Catalysis Mixed Function Oxygenases Adduct Turn (biochemistry) Hydroxylation chemistry.chemical_compound Multienzyme Complexes Organometallic Compounds Organic chemistry Computer Simulation Reactivity (chemistry) Binding Sites Chemistry Substrate (chemistry) General Chemistry Monooxygenase Computational Mathematics Models Chemical Density functional theory Imines Copper |
| Zdroj: | Journal of Computational Chemistry. 27:1950-1961 |
| ISSN: | 1096-987X 0192-8651 |
| DOI: | 10.1002/jcc.20502 |
| Popis: | Copper–oxygen complexes supported by β-diketiminate and anilido-imine ligands have recently been reported (Aboelella et al., J Am Chem Soc 2004, 126, 16896; Reynolds et al., Inorg Chem 2005, 44, 6989) as potential biomimetic models for dopamine β-monooxygenase (DβM) and peptidylglycine α-hydroxylating monooxygenase (PHM). However, in contrast to the enzymatic systems, these complexes fail to exhibit CH hydroxylation activity (Reynolds et al., Chem Commun 2005, 2014). Quantum chemical characterization of the 1:1 Cu-O2 model adducts and related species (Cu(III)-hydroperoxide, Cu(III)-oxo, and Cu(III)-hydroxide) indicates that the 1:1 Cu-O2 adducts are unreactive toward substrates because of the weakness of the OH bond that would be formed upon hydrogen-atom abstraction. This in turn is ascribed to the 1:1 adducts having both low reduction potentials and basicities. Cu(III)-oxo species on the other hand, determined to be intermediate between Cu(III)-oxo and Cu(II)-oxyl in character, are shown to be far more reactive toward substrates. Based on these results, design strategies for new DβM and PHM biomimetic ligands are proposed: new ligands should be made less electron rich so as to favor end-on dioxygen coordination in the 1:1 Cu-O2 adducts. Comparison of the relative reactivities of the various copper–oxygen complexes as hydroxylating agents provides support for a Cu(II)-superoxide species as the intermediate responsible for substrate hydroxylation in DβM and PHM, and suggests that a Cu(III)-oxo intermediate would be competent in this process as well. © 2006 Wiley Periodicals, Inc. J Comput Chem, 2006 |
| Databáze: | OpenAIRE |
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