نتایج جستجو برای: bromination

تعداد نتایج: 805  

Journal: :Canadian Journal of Chemistry 1967

Journal: :Chemical and Pharmaceutical Bulletin 1961

Journal: :Turkish Journal of Chemistry 2022

Known 1,6-di(thiophen-2-yl)hexane-1,6-dione (2) and novel 1,7-di(thiophen-2-yl)heptane-1,7-dione (4) were obtained from the reactions of thiophene with corresponding diacyl chlorides. Furthermore, compounds furan pyrrole units in place compound 2 same way. Bromination 4 gave bromides regioselectively. The reaction each HOAc medium yielded cyclocondensation products. In total, four known eleven ...

Journal: :Molecules 2016
David Georgiev Bartholomeus W H Saes Heather J Johnston Sarah K Boys Alan Healy Alison N Hulme

The mono ortho-bromination of phenolic building blocks by NBS has been achieved in short reaction times (15-20 min) using ACS-grade methanol as a solvent. The reactions can be conducted on phenol, naphthol and biphenol substrates, giving yields of >86% on gram scale. Excellent selectivity for the desired mono ortho-brominated products is achieved in the presence of 10 mol % para-TsOH, and the r...

Journal: :Organic & biomolecular chemistry 2013
Enxiang Wei Bing Liu Shaoxia Lin Baozhong Zhao Fushun Liang

The reaction of 1-alkenoylcyclopropane carboxylic acids with NBS or NIS was investigated, which provides an efficient route to biologically important 7-halogenated furo[3,2-c]pyran-4-ones in a one-pot transformation. The major pathway for the formation of the O-O heterocycles was proposed as a halo-oxa-cyclization, HBr elimination, cyclopropane ring-opening and recyclization (intramolecular oxa...

Journal: :The Journal of organic chemistry 2003
Matthew Kwok Wai Choi Helen Song He Patrick H Toy

We report herein a simple synthesis of 4-styryldiphenylphosphine and the radical copolymerization of it with styrene, both with and without a cross-linker, to directly form cross-linked and non-cross-linked polystyrene supported triphenylphosphine in which the level of phosphine incorporation can be easily and accurately controlled. The utility of these polymers is demonstrated by their use in ...

Journal: :Chemical science 2017
Hengtao Wang Xiunan Zhang Pingping Tang

The first total syntheses of schilancidilactones A and B, schilancitrilactone A, and 20-epi-schilancitrilactone A have been accomplished using a nickel-catalyzed cross coupling of alkyl bromide with vinyl stannane as the final step. The other key steps include late-stage C(sp3)-H bromination, the oxidative cleavage of a diol to provide the requisite ketone and ester for schilancidilactones A an...

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