Palladium-Catalyzed Asymmetric [4+2] Cycloaddition of 2-Methylidenetrimethylene Carbonate with Alkenes: Access to Chiral Tetrahydropyran-Fused Spirocyclic Scaffolds |
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| Authors: | Biming Mao Honglei Liu Zhengyang Yan Yi Xu Jiaqing Xu Wei Wang Yongjun Wu Prof Dr Hongchao Guo |
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| Institution: | 1. College of Science, China Agricultural University, 2 West Yuanmingyuan Road, Beijing, 100193 China;2. College of Public Health, Zhengzhou University, Zhengzhou, 450001 P. R. China |
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| Abstract: | A palladium-catalyzed asymmetric 4+2] cycloaddition of 2-methylidenetrimethylene carbonate with alkenes derived from pyrazolones, indandione, or barbiturate has been successfully developed, affording pharmacologically interesting chiral tetrahydropyran-fused spirocyclic scaffolds. The target compounds were generated in good to excellent yields and with high enantioselectivity (up to 99 % ee). Furthermore, this cycloaddition reaction could be efficiently scaled up, and several synthetic transformations were accomplished for the construction of other useful chiral spiropyrazolone and spiroindandione derivatives. |
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| Keywords: | asymmetric catalysis cycloaddition homogeneous catalysis palladium spirocyclic compounds |
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