Li Miao-Miao, Xiong Qin, Qu Bao-Le, Xiao Yu-Qing, Lan Yu, Lu Liang-Qiu, Xiao Wen-Jing
CCNU-uOttawa Joint Research Centre, Key Laboratory of Pesticide & Chemical Biology, Ministry of Education, College of Chemistry, Central China Normal University, 152 Luoyu Road, Wuhan, Hubei, 430079, China.
School of Chemistry and Chemical Engineering, Chongqing University, Chongqing, 400030, China.
Angew Chem Int Ed Engl. 2020 Sep 28;59(40):17429-17434. doi: 10.1002/anie.202006366. Epub 2020 Aug 11.
Vinylcyclopropanes (VCPs) are commonly used in transition-metal-catalyzed cycloadditions, and the utilization of their recently realized reactivities to construct new cyclic architectures is of great significance in modern synthetic chemistry. Herein, a palladium-catalyzed, visible-light-driven, asymmetric [5+2] cycloaddition of VCPs with α-diazoketones is accomplished by switching the reactivity of the Pd-containing dipolar intermediate from an all-carbon 1,3-dipole to an oxo-1,5-dipole. Enantioenriched seven-membered lactones were produced with good reaction efficiencies and selectivities (23 examples, 52-92 % yields with up to 99:1 er and 12.5:1 dr). In addition, computational investigations were performed to rationalize the observed high chemo- and periselectivities.
乙烯基环丙烷（VCPs）常用于过渡金属催化的环加成反应，利用其最近实现的反应活性构建新的环状结构在现代合成化学中具有重要意义。在此，通过将含钯偶极中间体的反应活性从全碳1,3-偶极转变为氧代-1,5-偶极，实现了钯催化、可见光驱动的VCPs与α-重氮酮的不对称[5+2]环加成反应。以良好的反应效率和选择性生成了对映体富集的七元内酯（23个例子，产率52-92%，对映体比例高达99:1，非对映体比例为12.5:1）。此外，还进行了计算研究，以合理解释观察到的高化学选择性和区域选择性。
