Sequential 1,4‐/1,2‐Addition of Lithium(trimethylsilyl)diazomethane onto Cyclic Enones to Induce C−C Fragmentation and N−Li Insertion
作者:Matthew J. O'Connor、Chunrui Sun、Xinyu Guan、Venkata R. Sabbasani、Daesung Lee
DOI:10.1002/anie.201510152
日期:2016.2.5
α,β‐Unsaturated ketones generally undergo addition reactions with nucleophiles with a preference for either 1,2‐ or 1,4‐addition, but rarely both. However, the right combination of reagents allows for consecutive 1,4‐ and 1,2‐additions to occur: Cyclic α,β‐unsaturated ketones undergo double additions with lithium(trimethylsilyl)diazomethane, effectively generating various molecular frameworks with
α,β-不饱和酮通常会与亲核试剂进行加成反应,偏爱1,2-或1,4-加成,但很少会同时发生。但是,正确的试剂组合可以连续发生1,4-和1,2-加成:环状α,β-不饱和酮与三甲基甲硅烷基重氮甲烷锂进行两次加成反应,有效地生成了具有复杂性和多样性的各种分子骨架。由于依次产生了多种反应性中间体,包括重氮烷烃衍生物和亚烷基卡宾,因此可以通过控制反应参数来诱导新的Grob型CC断裂,亚烷基卡宾介导的Li-N插入和偶极环加成反应。