Dibrominated addition and substitution of alkenes catalyzed by Mn<sub>2</sub>(CO)<sub>10</sub>
作者:Xianheng Song、Shanshui Meng、Hong Zhang、Yi Jiang、Albert S. C. Chan、Yong Zou
DOI:10.1039/d1cc04534b
日期:——
A practical method for the dibromination of alkenes without using molecular bromine is consistently appealing in organic synthesis. Herein, we report Mn-catalyzed dibrominated addition and substitution of alkenes only with N-bromosuccinimide, producing a variety of synthetically valuable dibrominated compounds in moderate to high yields.
A general procedure of 1,2-dibromination of vicinal sp3 C–H bonds of arylethanes using N-bromosuccinimide as the bromide reagent without an external initiator has been established. The modulation of the strength of the intermolecular noncovalent interactions between the solvent and arylethane ethanes, quantitatively evaluated via quantum chemical calculations, allows us to circumvent the fact that
Solvent shifts induced by dimethylsulphoxide in α-proton magnetic resonances of carbonyl compounds
作者:M.C. Cabaleiro、N.N. Giagante
DOI:10.1016/0040-4020(80)80082-2
日期:1980.1
The chemical shifts of α- and β-proton resonances of a number of carbonyl compounds in carbon tetrachloride and dimethylsulphoxide have been determined. The magnitude of the effect of the solvent change on the α-proton resonances seems to vary directly with its lability.
Catalysis by Ionic Liquid. A Green Protocol for the Stereoselective Debromination of <i>vicinal</i>-Dibromides by [pmIm]BF<sub>4</sub> under Microwave Irradiation
作者:Brindaban C. Ranu、Ranjan Jana
DOI:10.1021/jo051373r
日期:2005.10.1
[GRAPHIC]An easily accessible ionic liquid, 1-methyl-3-pentylimidazolium fluoroborate, [pmIm]BF4, has been demonstrated to be an efficient catalyst as well as reaction medium for the stereoselective debromination of a variety of structurally diverse vicinal-dibromides to the corresponding (E)-alkenes in high yields under microwave irradiation. This reaction does not require any organic solvent and any metal or any conventional reducing agent, and the ionic liquid is recycled without any appreciable loss of its catalytic efficiency.