Access to Enantiopure Triarylmethanes and 1,1-Diarylalkanes by NHC-Catalyzed Acylative Desymmetrization
Access to Enantiopure Triarylmethanes and 1,1-Diarylalkanes by NHC-Catalyzed Acylative Desymmetrization
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DOI：
10.1002/chem.201605445
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发表时间：
2017-02-01
影响因子：
4.3
通讯作者：
Zhao, Yu
中科院分区：
文献类型：
--
作者：
Lu, Shenci;Song, Xiaoxiao;Zhao, Yu
通过N-杂环卡宾催化双酚的酰化去对称化反应，我们提出了一种前所未有的、高效的、对映选择性的合成三芳基甲烷和1，1-二芳基烷烃的方法。这种方法利用容易获得的底物、试剂和简单的程序，以极好的对映体纯度提供有价值的产品。密度泛函理论计算表明，选择性是由四面体中间体的C-C键裂解步骤决定的，从而导致酯化产物。用分子内氢键和空间效应相结合的过渡态模型来解释这种对映体选择性。
We present herein an unprecedented, efficient and enantioselective synthesis of triarylmethanes and 1,1-diarylalkanes through N-heterocyclic carbene-catalyzed acylative desymmetrization of bisphenols. This method utilizes readily available substrates, reagents and a simple procedure to deliver the valuable products in excellent enantiopurity. DFT calculations reveal that the selectivity is governed by the C-C bond cleavage step of the tetrahedral intermediate leading to the ester product. A transition state model featuring a combination of intramolecular hydrogen bond and steric effect is developed to explain the enantioselectivity.