Synthesis of α,β-dibromo ketones by photolysis of α-bromo ketones with N-bromosuccinimide: Photoinduced β-bromination of α-bromo ketones
作者:Da Yoon Moon、Sejin An、Bong Ser Park
DOI:10.1016/j.tet.2019.130684
日期:2019.11
bond cleavage, elimination of HBr to give α,β-unsaturated ketone intermediates, and addition of Br2, which are formed by the reaction between HBr and NBS. From mechanistic studies of the reaction, we have also found a very convenient method for α-debromination of the α,β-dibromopropiophenones which is by simple irradiation of the dibromo ketones in acetone or 2-propanol without the use of any additives
在NBS的存在下照射α-溴丙苯酮会导致形成α,β-二溴苯乙酮,这可以看作是α-溴苯乙酮的β-溴化。该反应被认为经历了一系列反应。光诱导的C-Br键断裂,消除HBr,得到α,β-不饱和酮中间体,并添加Br 2是由HBr和NBS之间的反应形成的。从反应的机理研究中,我们还发现了一种非常方便的α,β-二溴苯乙酮的α-脱溴方法,该方法是在丙酮或2-丙醇中简单照射二溴酮,而无需使用任何添加剂。我们的结果表明,可以通过光化学方法将溴添加到羰基的α,β或两个位置上或从羰基的α,β或两个位置上消除,这使含溴羰基化合物的合成选择具有多种用途。