نتایج جستجو برای: bromination

تعداد نتایج: 805  

2017
Alette G.J. Ligtenbarg Ronald Hage Ben L. Feringa

Vanadium haloperoxidases catalyse the oxidation of halides leading to halogenation of substrates or, in the absence of suitable substrates, to oxidation of hydrogen peroxide into singlet oxygen and water. Furthermore, V-haloperoxidases are capable to give enantioselective sulfoxidation under the appropriate conditions. The most interesting model compounds that have been synthesised and studied ...

Isatin, N-methyl isatin and N-benzylisatin were smoothly monobrominated in the 5-position by treatment with pyridinium bromochromate (PBC) in acetic acid medium. In the similar conditions indigo underwent bromination and oxidation to give 5-bromoisatin in high yield.

Journal: :Journal of the American Chemical Society 2014
Koki Ikemoto Yasuhide Inokuma Kari Rissanen Makoto Fujita

Pd-mediated aromatic bromination is intriguing to synthetic and organometallic chemists due to both its synthetic utility and, more importantly, a proposed mechanism involving an uncommon Pd(IV)/Pd(II) catalytic cycle. Here, we report an X-ray snapshot observation of a Pd reaction center during a Pd-mediated aromatic bromination in a single crystal of a porous coordination network crystalline s...

Journal: :Chemical communications 2011
Luca Tortora Sara Nardis Frank R Fronczek Kevin M Smith Roberto Paolesse

Bromination of 3-nitro-5,10,15-triarylcorrole selectively provides two regioisomers, depending on the reaction pathway. An isocorrole species is the key intermediate to drive the reaction towards the 2-Br-17-nitro regioisomer.

Journal: :Chemical communications 2003
Zhihui Shao Jingbo Chen Yongqiang Tu Liang Li Hongbin Zhang

Bromination of an isolated double bond followed by aminocyclization furnishes a highly stereoselective protocol for the intramolecular formation of pyrrolidine and piperidine ring containing subunits that are presented in numerous biologically active natural products.

Journal: :Materials advances 2022

The bromination of poly(isobutylene- co -isoprene) rubber introduces a small amount bromide groups (1–2 mol%) to the elastomer backbone and creates new opportunities for functionalisation, as compared other saturated diene elastomers.

2003
Xian-Wei Li Etsuro Shibata Takashi Nakamura

Heat capacities, standard enthalpies of formation and entropies for 339 polybrominated/chlorinated dibenzo-p-dioxins (PXDDs) in the gas state were calculated using the density functional theory to construct a consistent set of thermodynamic values. The heat capacities and the entropies for PXDDs increase with increase in the substitute number of bromine and chlorine. As the degree of brominatio...

1999
Hélène G. Bazin Michael W. Wolff Robert J. Linhardt

The stereoselective synthesis of â-D-glucopyranosiduronic, R-L-idopyranosiduronic, and R-L-altropyranosiduronic acids has been performed from different ∆4-uronate monosaccharides. Bromination of the C-4,5 double bond provided the trans-diaxial bromohydrin derivatives, which were converted to the corresponding epoxides in high yields. Direct reduction of the epoxides using boranetetrahydrofuran ...

Journal: :Chemical and Pharmaceutical Bulletin 1963

Journal: :Nippon kagaku zassi 1950

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