A Catalytic Approach for Enantioselective Synthesis of Homoallylic Alcohols Bearing a <i>Z</i>-Alkenyl Chloride or Trifluoromethyl Group. A Concise and Protecting Group-Free Synthesis of Mycothiazole
作者:Ryan J. Morrison、Farid W. van der Mei、Filippo Romiti、Amir H. Hoveyda
DOI:10.1021/jacs.9b11178
日期:2020.1.8
catalytic processes and is expected to facilitate the preparation of bioactive organic molecules. More specifically, Z-chloro-substituted allylic pinacolatoboronate is first obtained through stereoretentive cross-metathesis between Z-crotyl-B(pin) (pin = pinacolato) and Z-dichloroethene, both of which are commercially available. The organoboron compound may be used in the central transformation of the entire
针对非对映选择性和对映选择性路线提出了一种无保护基团策略,可用于制备多种 Z-高烯丙醇,其效率明显高于其他可行方法。该方法需要合并几个催化过程,并有望促进生物活性有机分子的制备。更具体地说,Z-氯取代的烯丙基频哪醇硼酸酯首先通过 Z-巴豆基-B(pin) (pin = pinacolato) 和 Z-二氯乙烯之间的立体保留交叉复分解获得,这两种物质都可商购获得。有机硼化合物可用于整个方法的中心转化,即由质子活化的手性氨基苯酚硼基催化剂催化的醛的α-和对映选择性加成。然后催化交叉偶联可以以高对映体纯度提供所需的 Z-高烯丙醇。烯烃复分解步骤可以使用底物和可购买的基于 Mo 的复合物进行。第二个催化步骤所需的氨基苯酚化合物可以从廉价的起始材料以数克的量制备。还可以以类似的高效率和区域选择性、非对映选择性和对映选择性制备大量带有 Z-F3C 取代烯烃的高烯丙醇。此外,虽然α-选择性和对映选择性稍低,但可以以相似的效率获得三取代的