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.
Magnetic‐Nanoparticle‐Supported 2,2′‐Bis[3‐(triethoxysilyl)propyl]imidazolium‐Substituted Diethyl Ether Bis(tribromide): A Convenient Recyclable Reagent for Bromination
作者:Liqiang Wu、Zhikui Yin
DOI:10.1002/ejic.201300755
日期:2013.12.9
A new magnetic-nanoparticle-supported bromination reagent was synthesized by anchoring a 2,2′-bis[3-(triethoxysilyl)propyl]imidazolium-substituted diethylether bis(tribromide) onto the surface of γ-Fe2O3 nanoparticles and subsequently treating this new ionic liquid with bromine. The nanoparticle reagent was obtained with good loading levels and has been successfully used for the efficient bromination
Unsaturated hydrocarbons can easily be prepared in a few seconds starting from 1,2 dibromides in the presence of a catalytic amount of Nickel diphenylphosphinoethane dichloride (NidppeCl2) and tri.n.butyl tin hydride, (TBTH) at room temperature. The dependencie of the nature of starting dihalides is investigated.
Homolytic rearrangements of bicyclo[2.2.0]hexane and bicyclo[3.2.0]heptane
作者:John C. Walton
DOI:10.1039/p29880001371
日期:——
methylene groups of the C5 ring in bicyclo[3.2.0]heptane (15a). The bicyclo[3.2.0]heptan-2-yl radicals were observed by e.p.r. spectroscopy, as was their rearrangement, by stereoelectronically allowed β-scission, to 2-(cyclopent-2-enyl)ethyl radicals. Bromine atoms abstract hydrogen from (15a) and no SH2 reaction was detected. The radicals and their rearrangements were studied by semi-empirical MINDO/3
自由基从双环[2.2.0]己烷中的桥位和桥头位都提取氢(4)。通过epr光谱法观察到双环[2.2.0]己烷-1-基。双环[2.2.0]己-2-基通过立体电子禁止的β-断裂重排,得到环己-3-烯基。与其他环丁烷不同,化合物(4)与溴原子进行S H 2反应。自由基夺取氢仅从C的亚甲基基团5环双环[3.2.0]庚烷(15A)。通过epr光谱法观察到双环[3.2.0]庚-2-基,以及通过立体电子允许的β-断裂将其重排为2-(环戊-2-烯基)乙基。溴原子从(15a)提取氢,未检测到S H 2反应。使用半经验MINDO / 3和MNDO方法研究了自由基及其重排。