Total Synthesis and Biological Evaluation of the Resveratrol-Derived Polyphenol Natural Products Hopeanol and Hopeahainol A
作者:K. C. Nicolaou、Qiang Kang、T. Robert Wu、Chek Shik Lim、David Y.-K. Chen
DOI:10.1021/ja102623j
日期:2010.6.2
The totalsynthesis and biological evaluation of the resveratrol-derived natural products hopeanol (2) and hopeahainol A (3) in their racemic and antipodal forms are described. The Friedel-Crafts-based synthetic strategy employed was developed from model studies that established the feasibility of constructing the C(7b) quaternary center through an intramolecular Friedel-Crafts reaction and a Grob-type
描述了白藜芦醇衍生的天然产物hopeanol (2) 和hopahainol A (3) 的外消旋和对映形式的全合成和生物学评价。所采用的基于 Friedel-Crafts 的合成策略是根据模型研究开发的,该模型研究确定了通过分子内 Friedel-Crafts 反应和 Grob 型断裂构建 C(7b) 四元中心的可行性,以在生长的分子中引入强制性烯烃键. 合成的最后阶段涉及环氧化物底物和分子内 Friedel-Crafts 反应,然后氧化以在全局脱保护后提供 Hopeahainol A (3)。后者在碱性条件下被转化为hopahainol (2),而逆向转化,之前建议作为hopahainol A (3) 生物合成中的一个步骤,在各种条件下都没有观察到。对合成化合物的生物学评价证实了希望醇 A (3) 的乙酰胆碱酯酶抑制活性,但没有确认希望醇 (2) 的细胞毒性效力。
Reductive Amination of Ketonic Compounds Catalyzed by Cp*Ir(III) Complexes Bearing a Picolinamidato Ligand
Cp*Ir complexes bearing a 2-picolinamide moiety serve as effective catalysts for the direct reductive amination of ketoniccompounds to give primary amines under transfer hydrogenation conditions using ammonium formate as both the nitrogen and hydrogen source. The clean and operationally simple transformation proceeds with a substrate to catalyst molar ratio (S/C) of up to 20,000 at relatively low