نتایج جستجو برای: intermediate radical

تعداد نتایج: 219788  

Journal: :Chemical communications 2011
Rita Beel Stefanie Kobialka Martin L Schmidt Marianne Engeser

SOMO catalysis has lately obtained large interest as a new and powerful version of enantioselective organocatalysis which includes radical steps initiated by a one-electron oxidation. The intermediate enamine radical cation has been postulated, but has not been observed directly so far. This communication now reports the direct detection of this key intermediate.

Journal: :Dalton transactions 2010
Hiroshi Nakajima Kalaivani Ramanathan Naomi Kawaba Yoshihito Watanabe

In a previous study, we constructed a prototype thermally tolerant artificial peroxidase from an electron transfer protein, cytochrome c(552) from Thermus thermophilus, and demonstrated that engineering of proteins from thermophiles could be a promising methodology to produce artificial enzymes for practical use. In the present study, further improvement of the prototype (the V49D/M69A mutant) ...

Journal: :Chemical research in toxicology 1998
P H Toy M Newcomb L P Hager

The oxidation of hypersensitive radical probes by chloroperoxidase from Caldariomyces fumago (CPO) was studied in an attempt to "time" a putative radical intermediate. Oxidation of (trans-2-phenylcyclopropyl)methane, previously studied by Zaks and Dodds [Zaks, A., and Dodds, D. R. (1995) J. Am. Chem. Soc. 115, 10419-10424] was reinvestigated. Unrearranged oxidation products were found as previo...

2017
Xiaotian Qi Lei Zhu Ruopeng Bai Yu Lan

Transition metal-catalyzed radical-radical cross-coupling reactions provide innovative methods for C-C and C-heteroatom bond construction. A theoretical study was performed to reveal the mechanism and selectivity of the copper-catalyzed C-N radical-radical cross-coupling reaction. The concerted coupling pathway, in which a C-N bond is formed through the direct nucleophilic addition of a carbon ...

2016
Shaofei Wu Wenxi Wang Minchan Li Lujie Cao Fucong Lyu Mingyang Yang Zhenyu Wang Yang Shi Bo Nan Sicen Yu Zhifang Sun Yao Liu Zhouguang Lu

It is a challenge to prepare organic electrodes for sodium-ion batteries with long cycle life and high capacity. The highly reactive radical intermediates generated during the sodiation/desodiation process could be a critical issue because of undesired side reactions. Here we present durable electrodes with a stabilized α-C radical intermediate. Through the resonance effect as well as steric ef...

Journal: :Nature communications 2016
Yusuke Hibi Makoto Ouchi Mitsuo Sawamoto

There is a growing interest in sequence-controlled polymers toward advanced functional materials. However, control of side-chain order for vinyl polymers has been lacking feasibility in the field of polymer synthesis because of the inherent feature of chain-growth propagation. Here we show a general and versatile strategy to control sequence in vinyl polymers through iterative radical cyclizati...

Journal: :Inorganic chemistry 2005
Charles J Walsby Danilo Ortillo Jian Yang Mbako R Nnyepi William E Broderick Brian M Hoffman Joan B Broderick

Electron paramagnetic resonance (EPR), electron-nuclear double resonance (ENDOR), and Mössbauer spectroscopies and other physical methods have provided important new insights into the radical-SAM superfamily of proteins, which use iron-sulfur clusters and S-adenosylmethionine to initiate H atom abstraction reactions. This remarkable chemistry involves the generation of the extremely reactive 5'...

Journal: :Organic letters 2014
Yu Du Yuhuang Wang Xin Li Yaling Shao Guohui Li Richard D Webster Yonggui Robin Chi

An unprecedented N-heterocyclic carbene catalytic reductive β,β-carbon coupling of α,β-nitroalkenes, by using an organic substrate to mimic the one-electron oxidation role of the pyruvate ferredoxin oxidoreductase (PFOR) in living systems, has been developed. The reaction goes through a radical anion intermediate generated under a catalytic redox process. For the first time, the presence of rad...

Journal: :Angewandte Chemie 2013
Rong Zhu Stephen L Buchwald

A method for the efficient enantioselective oxytrifluoromethylation of alkenes has been developed using a copper catalyst system. Mechanistic studies are consistent with a metal-catalyzed redox radical addition mechanism, in which a C–O bond is formed via the copper-mediated enantioselective trapping of a prochiral alkyl radical intermediate derived from the initial trifluoromethyl radical addi...

نمودار تعداد نتایج جستجو در هر سال

با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید