Stereoselective Synthesis of Axially Chiral Natural Products, (−)-Steganone and O,O′-Dimethylkorupensamine A, Utilizing Planar Chiral (Arene)chromium Complexes
作者:Ken Kamikawa、Takashi Watanabe、Akira Daimon、Motokazu Uemura
DOI:10.1016/s0040-4020(99)01115-1
日期:2000.4
substituent of arylboronic acids and reaction conditions. The cross-coupling with o-alkyl or hydroxymethyl substituted arylboronic acids gave kinetically controlled products in which the ortho substituents were oriented in syn-configuration to the tricarbonylchromium fragment. On the other hand, o-formyl phenylboronic acid produced thermodynamically stable anti-coupling products under the same conditions
钯(0)介导的碳酸钠存在下,在甲醇水溶液中回流下,平面手性(2,6-二取代溴苯)铬配合物与邻取代芳基硼酸的平面手性(2,6-二取代溴苯)铬络合物的Suzuki-Miyaura交叉偶联产生立体选择性的轴向手性单Cr(CO )3层-complexed的联芳基。发现交叉偶联产物的轴向立体化学很大程度上取决于芳基硼酸的邻取代基的空间体积和反应条件。与邻烷基或羟甲基取代的芳基硼酸的交叉偶联产生动力学控制的产物,其中邻位取代基在顺式中取向-对三羰基铬片段的构型。另一方面,邻甲酰基苯基硼酸在相同条件下产生热力学稳定的抗偶联产物。通过利用这些方法的,生物活性轴向手性天然产物,( - ) - steganone和ø,ö ' -二甲基衍生物korupensamine A的天然产物的,被立体选择性合成。