本文我们报告一个新的和更实际的方法来制备宝石从末端炔烃,四溴甲烷(CBR -dibromoenones 4在单个步骤中),和水。机理研究表明,在过硫酸盐(K 2 S 2 O 8)的帮助下生成三溴甲基自由基对于这种转化是必不可少的。该反应具有易得的化学品、广泛的底物范围、绿色溶剂和温和的反应条件,为构建卤素取代的烯酮提供了有效的替代方案。
BrCCl3 and CBr4 was develop, enabling Kharasch-type addition/nucleophilic substitution cascade to selectively produce α-gem-dihalovinyl ketones and chromen-2-ones with moderate to good yields. Use of monoalkynes without additional nucleophilic sites furnished α-gem-dihalovinyl ketonesthrough a Kharasch-type addition and intermolecular allylic substitution cascade whereas the latter transformation of 2-ethynylphenols