An Enantioselective, Intermolecular α-Arylation of Ester Enolates To Form Tertiary Stereocenters
An Enantioselective, Intermolecular α-Arylation of Ester Enolates To Form Tertiary Stereocenters
复制标题
DOI：
10.1021/ja2066829
复制
发表时间：
2011-10-12
影响因子：
15
通讯作者：
Zhou, Jianrong (Steve)
中科院分区：
文献类型：
--
作者：
Huang, Zhiyan;Liu, Zheng;Zhou, Jianrong (Steve)
在过渡金属催化的羰基化合物的不对称α-芳基化反应中，由于单芳基化产物容易烯醇化，形成具有高对映选择性的叔中心是一个长期存在的问题。在此，我们报道了使用由新的（R）-H-8-BINOL衍生的单膦负载的钯催化剂的这样的实施例。甲硅烷基乙烯酮缩醛与弱碱性活化剂一起用作酯阴离子的等价物，它们与芳基三氟甲磺酸酯以优异的对映体过量（ee）顺利地反应。该反应的有用性在92%ee的（S）-萘普生的克级合成中得到证明。
In transition-metal catalyzed, asymmetric alpha-arylation of carbonyl compounds, formation of tertiary centers with high enantioselectivity is a longstanding problem, due to easy enolization of the monoarylation products. Herein, we report such examples using a palladium catalyst supported by a new, (R)-H-8-BINOL-derived monophosphine. Silyl ketene acetals, together with a weakly basic activator, were used as equivalents of ester anions, and they reacted smoothly with aryl triflates in excellent enantiomeric excess (ee). The usefulness of the reaction was demonstrated in a gram-scale synthesis of (S)-Naproxen in 92% ee.