Mild and Efficient Vicinal Dibromination of Olefins Mediated by Aqueous Ammonium Fluoride
作者:Tony Shing、Ying-Yeung Yeung、Wing Ng
DOI:10.1055/s-0036-1588506
日期:2018.3
A mild and efficient vicinal dibromination of olefins has been developed by using saturated aqueous ammonium fluoride solution as the promoter. Inexpensive and commercially available N -bromosuccinimide (NBS) was used as the brominating reagent. The corresponding vicinal dibromoalkanes could be obtained in good to excellent yields.
We report herein a regio‐ and stereoselective photocatalytic hydrogenolysis of allylicalcohols to form unsaturated hydrocarbons employing a palladium(II)‐loaded titanium oxide; the reaction proceeds at room temperature under light irradiation without stoichiometric generation of salt wastes. Olefin and saturated alcohol moieties tolerated the reaction conditions. Hydrogen atoms were selectively incorporated
A highly diastereoselective pyrrolidine-promoted dibromination of alkenes by combination of NBS and succinimide is presented. The pyrrolidine-mediated dibromination of alkenes is higly anti-selective and gives the corresponding products in moderate to high yields and up to >25:1 dr.
A versatile method for a catalytic bromination reaction: The oxidativebromination reaction of arenes, alkenes, and alkynes proceeded underatmosphericoxygen in the presence of a catalytic amount of NH4VO3, a bromide source, and an acid. A bromonium cation‐like species is proposed to be involved.
催化溴化反应的一种通用方法:芳烃,烯烃和炔烃的氧化溴化反应是在大气中氧气,催化量的NH 4 VO 3,溴化物源和酸的存在下进行的。拟议涉及一种溴阳离子类物质。
A General Method for the Dibromination of Vicinal sp<sup>3</sup> C–H Bonds Exploiting Weak Solvent–Substrate Noncovalent Interactions
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