Trivalent Phosphine-Catalyzed [4+1] Spiro-annulation Reaction Using Allenyl Imide and Methylene Cyclocompounds
作者:Zi-Qiu Zhang、Zhen-Kai Zhang、Yu-Hao Wang、Bo-Ting Chen、Feng-Kai He、Yi-Long Wang、Tao Shu、Yi-Yong Huang
DOI:10.1021/acs.joc.4c00388
日期:——
The trivalent phosphine-catalyzed [4+1] spiro-annulation reaction of allenyl imide and activated methylene cyclocompounds has been developed for the construction of various spiro-2-cyclopenten-1-ones. Oxindoles, 3-isochromanones, and 2-indanones are selected as 1C synthons to capture the in situ-generated bis-electrophilic α,β-unsaturated ketenyl phosphonium intermediate, affording the corresponding
联烯基酰亚胺和活化的亚甲基环化合物的三价膦催化的[4+1]螺环化反应已被开发用于构建各种螺-2-环戊烯-1-酮。选择羟吲哚、3-异色满酮和 2-茚满酮作为 1C 合成子,捕获原位生成的双亲电子 α,β-不饱和烯基鏻中间体,以良好至优异的产率提供相应的单螺环和双螺环戊烯酮(≤ 91%)在温和条件下。使用单膦 ( R )-SITCP 进行不对称催化的初步尝试提供了有希望的对映选择性 (45% ee)。还提出了一种合理的反应机制。