98%
921
2 minutes
20
Terminal cobalt(IV)-oxo (Co-O) species have been implicated as key intermediates in various cobalt-mediated oxidation reactions. Herein we report the photocatalytic generation of a mononuclear non-haem [(13-TMC)Co(O)] (2) by irradiating [Co(13-TMC)(CFSO)] (1) in the presence of [Ru(bpy)], NaSO, and water as an oxygen source. The intermediate 2 was also obtained by reacting 1 with an artificial oxidant (that is, iodosylbenzene) and characterized by various spectroscopic techniques. In particular, the resonance Raman spectrum of 2 reveals a diatomic Co-O vibration band at 770 cm, which provides the conclusive evidence for the presence of a terminal Co-O bond. In reactivity studies, 2 was shown to be a competent oxidant in an intermetal oxygen atom transfer, C-H bond activation and olefin epoxidation reactions. The present results lend strong credence to the intermediacy of Co-O species in cobalt-catalysed oxidation of organic substrates as well as in the catalytic oxidation of water that evolves molecular oxygen.
Download full-text PDF |
Source |
---|---|
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5376677 | PMC |
http://dx.doi.org/10.1038/ncomms14839 | DOI Listing |
Nature
May 2021
Department of Molecular Biosciences, University of Texas at Austin, Austin, 78712, Texas, USA.
Nat Rev Chem
August 2020
Department of Chemistry and Nano Science, Ewha Womans University, Seoul, Korea.
High-valent metal-oxo species with multiply-bonded M-O groups have been proposed as key intermediates in many biological and abiological catalytic oxidation reactions. These intermediates are implicated as active oxidants in alkane hydroxylation, olefin epoxidation and other oxidation reactions. For example, [FeO(porphyrinato)] cofactors bearing π-radical porphyrinato ligands oxidize organic substrates in cytochrome P450 enzymes, which are common to many life forms.
View Article and Find Full Text PDFFEMS Microbiol Lett
July 2019
Mohammed V University, Laboratory of Biology of Human Pathologies, Department of Biology, Faculty of Sciences, Ibn-Batouta Avenue, P.O. Box 1014, Rabat, Morocco.
Aerobic degradation of the sterol tetracyclic nucleus by microorganisms comprises the catabolism of A/B-rings, followed by that of C/D-rings. B-ring rupture at the C9,10-position is a key step involving 3-ketosteroid Δ1-dehydrogenase (KstD) and 3-ketosteroid 9α-hydroxylase (KstH). Their activities lead to the aromatization of C4,5-en-containing A-ring causing the rupture of B-ring.
View Article and Find Full Text PDFNat Prod Rep
August 2018
Department of Chemistry, Boston University, Boston, MA 02215, USA.
Covering: up to 2018 α-Ketoglutarate (αKG, also known as 2-oxoglutarate)-dependent mononuclear non-haem iron (αKG-NHFe) enzymes catalyze a wide range of biochemical reactions, including hydroxylation, ring fragmentation, C-C bond cleavage, epimerization, desaturation, endoperoxidation and heterocycle formation. These enzymes utilize iron(ii) as the metallo-cofactor and αKG as the co-substrate. Herein, we summarize several novel αKG-NHFe enzymes involved in natural product biosyntheses discovered in recent years, including halogenation reactions, amino acid modifications and tailoring reactions in the biosynthesis of terpenes, lipids, fatty acids and phosphonates.
View Article and Find Full Text PDFNat Commun
June 2017
State Key Laboratory of Coordination Chemistry, Institute of Chemistry and BioMedical Sciences, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, China.
Synthetic methods inspired by Nature often offer unique advantages including mild conditions and biocompatibility with aqueous media. Inspired by an ergothioneine biosynthesis protein EgtB, a mononuclear non-haem iron enzyme capable of catalysing the C-S bond formation and sulfoxidation, herein, we discovered a mild and metal-free C-H sulfenylation/intramolecular rearrangement cascade reaction employing an internally oxidizing O-N bond as a directing group. Our strategy accommodates a variety of oxyamines with good site selectivity and intrinsic oxidative properties.
View Article and Find Full Text PDF