化学学报 ›› 2017, Vol. 75 ›› Issue (8): 798-807.DOI: 10.6023/A17040190 上一篇    下一篇

研究论文

Cortistatin类型天然产物的不对称形式全合成:金催化串联Semi-Pinacol重排反应策略

顾月青a, 袁浩a, 傅俊凯b, 龚建贤a, 杨震a,c   

  1. a 北京大学深圳研究生院 化学生物学与生物技术学院 化学基因组学实验室 深圳 518055;
    b 东北师范大学 化学学院 吉林省有机功能分子设计与合成重点实验室 长春 130024;
    c 北京大学 化学与分子工程学院/北大清华生命联合中心 北京分子科学国家实验室 生物有机与分子工程教育部 重点实验室 北京 100871
  • 收稿日期:2017-04-28 出版日期:2017-08-15 发布日期:2017-06-08
  • 通讯作者: 杨震,E-mail:zyang@pku.edu.cn;傅俊凯,fujk109@nenu.edu.cn;龚建贤,gongjx@pkusz.edu.cn E-mail:zyang@pku.edu.cn;fujk109@nenu.edu.cn;gongjx@pkusz.edu.cn
  • 基金资助:

    项目受国家自然科学基金(Nos.21372016,21572009 and 21632002)资助.

Asymmetric Formal Synthesis of Cortistatins via a Gold-Catalyzed Semi-Pinacol Rearrangement Strategy

Gu Yueqinga, Yuan Haoa, Fu Junkaib, Gong Jianxiana, Yang Zhena,c   

  1. a Laboratory of Chemical Genomics, School of Chemical Biology and Biotechnology, Peking University Shenzhen Graduate School, Shenzhen 518055, China;
    b Jilin Province Key Laboratory of Organic Functional Molecular Design & Synthesis, Department of Chemistry, Northeast Normal University, Changchun 130024, China;
    c Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education, Beijing National Laboratory for Molecular Science, College of Chemistry and Molecular Engineering, and Peking-Tsinghua Center for Life Sciences, Peking University, Beijing 100871, China
  • Received:2017-04-28 Online:2017-08-15 Published:2017-06-08
  • Contact: 10.6023/A17040190 E-mail:zyang@pku.edu.cn;fujk109@nenu.edu.cn;gongjx@pkusz.edu.cn
  • Supported by:

    Project supported by the National Natural Science Foundation of China (Nos.21372016,21572009 and 21632002).

本工作详细报道了Cortistatin类型天然产物不对称形式全合成的研究路线.以近期作者发展的金催化串联semi-pinacol重排反应构建[3,2,1]七元氧桥环结构的方法学为基础,进一步将其应用于复杂体系,高效构建了Cortistatin类型天然产物独特的七元氧桥环核心骨架,从而完成了该类型天然产物的不对称形式全合成.

关键词: 金催化, 氧桥环, 形式全合成, semi-pinacol重排, Cortistatins

Over the past decade, Gold complexes have emerged as efficient and mild catalysts for the transformation of substrates possessing alkyne functionality into a range of useful scaffolds. These powerful methods have enabled the development of novel approaches for the total synthesis of biologically active natural products by gold catalysis. In this case, we found that the intramolecular nucleophilic addition of a hydroxyl group to a carbon-carbon triple bond, which activated by a gold catalyst, followed by further useful transformation has proven to be an excellent method for rapid construction of structural diversity of molecular scaffolds. The cortistatins are a family of 11 steroidal alkaloids which exhibit significant biological activities. The intriguing biological properties and their low natural abundance have elevated cortistatins to be a typical target for both partial and total synthesis. Up to now, more than a dozen research groups have published approaches directed toward the synthesis of cortistatins, including one semi-synthesis, five total syntheses and five formal syntheses, as well as a number of synthetic studies about the pentacyclic core and some illuminating model studies. One of the biggest challenges for the synthesis of cortistatins is how to construct the unprecedented oxabicyclo[3.2.1]octane ring system which lies within a complex tetracarbocyclic skeleton. In our previous work, we have developed a gold-catalyzed semi-pinacol rearrangement strategy to diastereoselective synthesis of the oxabicyclo[3.2.1]octane ring system. The wide substrate scope as well as the high diastereoselectivity have made us to apply this method into the asymmetric formal synthesis of Cortistatins. Herein, full details about our efforts towards the formal synthesis of cortistatins were described by employing our developed gold-catalyzed cascade reaction to oxabicyclo[3.2.1]octane ring systems. This route is featured with a novel gold-catalyzed cascade reaction involving intramolecular nucleophilic addition of hydroxyl group to the carbon-carbon triple bond, followed by an oxonium ion initiated semi-pinacol-type 1,2-migration to construct the key oxabicyclo[3.2.1]octane skeleton.

Key words: gold catalysis, oxabicyclo[3.2.1]octane skeletons, formal synthesis, semi-pinacol rearrangement, Cortistatins