Utilizing Vinylcyclopropane Reactivity: Palladium‐Catalyzed Asymmetric [5+2] Dipolar Cycloadditions
作者:Miao‐Miao Li、Qin Xiong、Bao‐Le Qu、Yu‐Qing Xiao、Yu Lan、Liang‐Qiu Lu、Wen‐Jing Xiao
DOI:10.1002/anie.202006366
日期:2020.9.28
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
乙烯基环丙烷(VCP)通常用于过渡金属催化的环加成反应中,利用其最近实现的反应活性来构建新的环状结构在现代合成化学中具有重要意义。在此,通过将含钯的偶极中间体的反应性从全碳1,3偶极转换为钯,可催化可见光驱动的,具有α-重氮酮的VCP的不对称[5 + 2]环加成反应。 1,5,5偶极子 对映体富集的七元内酯具有良好的反应效率和选择性(23个实例,产率为52–92%,er最高为99:1,dr为12.5:1)。此外,进行了计算研究以合理化所观察到的高化学选择性和高选择性。