Utilizing Vinylcyclopropane Reactivity: Palladium-Catalyzed Asymmetric [5+2] Dipolar Cycloadditions |
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Authors: | Miao-Miao Li Qin Xiong Bao-Le Qu Yu-Qing Xiao Prof. Yu Lan Prof. Liang-Qiu Lu Prof. Wen-Jing Xiao |
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Affiliation: | 1. 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;2. School of Chemistry and Chemical Engineering, Chongqing University, Chongqing, 400030 China |
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Abstract: | 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. |
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Keywords: | asymmetric catalysis cycloaddition ketenes medium-sized rings palladium |
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