镍( II )催化的γ-烷基单取代的α,β-不饱和丁内酰胺与α,β-不饱和羰基化合物的不对称直接乙烯基Michael加成,以良好的收率和令人满意的对映选择性得到γ,γ-二烷基取代的丁内酰胺。基于该反应还开发了串联催化不对称插烯迈克尔加成/分子内迈克尔加成,这使得能够构建具有三个连续立体碳中心的对映体富集的八氢吲哚。
Access to Fused Tricyclic γ-Butyrolactones, A Natural Product-like Scaffold
作者:Hanuman P. Kalmode、Kishor L. Handore、D. Srinivasa Reddy
DOI:10.1021/acs.joc.7b00794
日期:2017.7.21
Serendipitous findings of an acid mediated skeletal rearrangement of bicyclo-β-ketoester having cyclopropyl ring to access fused tricyclic γ-butyrolactones has been described. This novel transformation has been optimized to 30 mol% p-toluenesulfonic acid (p-TSA) in toluene using Dean–Stark apparatus, where the aldol condensation, cyclopropyl ringopening followed by cyclization took place in a single-pot