Scalable,Stereocontrolled Formal Syntheses of (+)‐Isoschizandrin and (+)‐Steganone: Development and Applications of Palladium(II)‐Catalyzed Atroposelective C−H Alkynylation |
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| Authors: | Gang Liao Qi‐Jun Yao Zhuo‐Zhuo Zhang Yong‐Jie Wu Dan‐Ying Huang Prof?Dr Bing‐Feng Shi |
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| Institution: | 1. http://mypage.zju.edu.cn/en/bfshi/;2. Department of Chemistry, Zhejiang University, Hangzhou, China;3. School of Chemical and Environmental Engineering, Wuyi University, Jiangmen, China;4. State Key Laboratory of Elemento-organic Chemistry, Nankai University, Tianjin, China |
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| Abstract: | Dibenzocyclooctadiene lignans are an interesting class of molecules because of their unique structure based on an axially chiral biaryl moiety as well as their significant biological activity. Herein, we describe the development of a palladium‐catalyzed atroposelective C?H alkynylation and its application in gram‐scale, stereocontrolled formal syntheses of (+)‐isoschizandrin and (+)‐steganone. tert‐Leucine was identified as an efficient, catalytic transient chiral auxiliary. A wide range of enantiomerically enriched biaryl compounds were prepared by this approach in good yields (up to 99 %) with excellent enantioselectivity (up to >99 % ee). |
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| Keywords: | atroposelectivity C− H alkynylation formal synthesis homogeneous catalysis natural products |
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