90-46-0Relevant articles and documents
A highly reactive P450 model compound I
Bell, Seth R.,Groves, John T.
, p. 9640 - 9641 (2009)
(Graph Presented) The detection and kinetic characterization of a cytochrome P450 model compound I, [OFeIV-4-TMPyP]+ (1), in aqueous solution shows extraordinary reaction rates for C-H hydroxylations. Stopped-flow spectrophotometric monitoring of the oxidation of Fe III-4-TMPyP with mCPBA revealed the intermediate 1, which displays a weak, blue-shifted Soret band at 402 nm and an absorbance at 673 nm, typical of a porphyrin π-radical cation. This intermediate was subsequently transformed into the well-characterized OFeIV-4-TMPyP. Global analysis afforded a second-order rate constant k1 = (1.59 ± 0.06) × 10 7 M-1 s-1 for the formation of 1 followed by a first-order decay with k2 = 8.8 ± 0.1 s-1. 1H and 13C NMR determined 9-xanthydrol to be the major product (～90% yield) of xanthene oxidation by 1. Electrospray ionization mass spectrometry carried out in 47.5% 18OH2 indicated 21% 18O incorporation, consistent with an oxygen-rebound reaction scenario. Xanthene/xanthene-d2 revealed a modest kinetic isotope effect, kH/kD = 2.1. Xanthene hydroxylation by 1 occurred with a very large second-order rate constant k3 = (3.6 ± 0.3) × 106 M-1 s-1. Similar reactions of fluorene-4-carboxylic acid and 4-isopropyl- and 4-ethylbenzoic acid also gave high rates for C-H hydroxylation that correlated well with the scissile C-H bond energy, indicating a homolytic hydrogen abstraction transition state. Mapping the observed rate constants for C-H bond cleavage onto the Bronsted- Evans-Polanyi relationship for similar substrates determined the H-OFe IV-4-TMPyP bond dissociation energy to be ～100 kcal/mol. The high kinetic reactivity observed for 1 is suggested to result from a high porphyrin redox potential and spin-state-crossing phenomena. More generally, subtle charge modulation at the active site may result in high reactivity of a cytochrome P450 compound I.
Manganese(Ⅲ)-iodosylbenzene complex, preparation method thereof and oxidant comprising the same
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Paragraph 0130-0136; 0141; 0166, (2020/09/22)
The present invention relates to a manganese(III)-iodosylbenzene complex, a preparation method thereof, and an oxidant comprising the same. The manganese(III)-iodosylbenzene complex provided in one aspect of the present invention has an effect of inducing a hydrogen atom abstraction (HAA) reaction of cyclohexadiene, dihydroanthracene and xanthine, and an oxygen atom transfer (OAT) reaction of thioanisole and stilbene with excellent electrophilic reactivity. The manganese(III)-iodosylbenzene complex is represented by a compound of formula 1: [Mn^III(L)(OIPh)(OH)]^2+.COPYRIGHT KIPO 2020
CoI-Catalyzed Barbier Reactions of Aromatic Halides with Aromatic Aldehydes and Imines
Presset, Marc,Paul, Jér?me,Cherif, Ghania Nait,Ratnam, Nisanthan,Laloi, Nicolas,Léonel, Eric,Gosmini, Corinne,Le Gall, Erwan
supporting information, p. 4491 - 4495 (2019/02/27)
The reductive Barbier coupling of aromatic halides and electrophiles has been achieved using a CoBr2/1,10-phenanthroline catalytic system and over stoichiometric amounts of zinc. The reaction displayed a broad scope of substrates, including (hetero)aryl chlorides as pro-nucleophiles and aldehydes or imines as electrophiles, leading to diarylmethanols and diarylmethylamines in moderate to excellent yields, respectively.
