Organocatalytic regioselective asymmetric Michael addition of azlactones to o-hydroxy chalcone derivatives.
Organocatalytic regioselective asymmetric Michael addition of azlactones to o-hydroxy chalcone derivatives.
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DOI：
10.1039/c5ob00121h
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发表时间：
2015-05
影响因子：
3.2
通讯作者：
Shao‐Yun Zhang;G. Ruan;Zhicong Geng;Naiying Li;Ming-can Lv;Yong Wang;Xing-Wang Wang-Xing-Wang-Wang-2426252
中科院分区：
文献类型：
--
作者：
Shao‐Yun Zhang;G. Ruan;Zhicong Geng;Naiying Li;Ming-can Lv;Yong Wang;Xing-Wang Wang-Xing-Wang-Wang-2426252
报道了吖内酯与邻羟基查耳酮衍生物之间的区域选择性和对映选择性Michael加成反应。具有两个连续立体中心的对映体富集的N，O-缩胺以中等至良好的产率独家获得，具有优异的非对映选择性和良好至优异的对映选择性。实验结果表明，在查尔酮衍生物的肉桂烯基上的邻羟基在区域选择性Michael加成反应的反应位点上起着至关重要的作用。此外，利用圆二色性光谱和密度泛函理论研究了N，O-缩胺化合物的绝对构型和过渡态结构。
The regioselective and enantioselective Michael addition between azlactones and o-hydroxy chalcone derivatives is reported. Enantiomerically enriched N,O-aminals with two continuous stereogenic centers are exclusively obtained in moderate to good yields with excellent diastereoselectivities and good to excellent enantioselectivities. The experimental results show that an o-hydroxy group on the cinnamenyl motif of chalcone derivatives plays a crucial role at the reaction sites for the regioselective Michael addition. In addition, circular dichroism (CD) spectroscopy and density functional theory (DFT) are used to investigate the absolute configuration of N,O-aminals and the corresponding transition-state structures.