α-N-acyliminium ion - 2-bromoalkene cyclizations.
作者:Jean-Pierre Gesson、Jean-Claude Jacquesy、Didier Rambaud
DOI:10.1016/s0040-4020(01)80367-7
日期:1993.3
The cyclization of α-N-acyliminium ions generated from ethoxylactams 1–3 using trifluoroacetic acid, trifluoromethanesulfonic acid and anhydrous HF affords ketones, bromoalkenes and geminal bromofluoro compounds, respectively. A non concerted process explains these results which demonstrate the high reactivity of the intermediate bromocarbenium ions with different nucleophiles. The unexpected fluorination
使用三氟乙酸,三氟甲磺酸和无水HF将乙氧基内酰胺1-3生成的α-N-酰基亚胺离子环化,分别得到酮,溴代烯烃和双溴代氟化合物。一个不协调的过程解释了这些结果,这些结果证明了中间溴碳鎓离子与不同亲核试剂的高反应性。在简单的烯烃中也观察到了在HF中观察到的意外氟化反应,这产生了差向异构氟衍生物的混合物。