Podand-Based Dimeric Chromium(III)-Salen Complex for Asymmetric Henry Reaction: Cooperative Catalysis Promoted by Complexation of Alkali Metal Ions
文献类型：期刊论文
| 作者 | Ouyang, Guang-Hui; He, Yan-Mei; Fan, Qing-Hua |
| 刊名 | CHEMISTRY-A EUROPEAN JOURNAL
 |
| 出版日期 | DEC 8 2014 |
| 卷号 | 20期号:50页码:16454-16457 |
| 英文摘要 | alpha-Branched ketones remain a challenging type of substrates in aminocatalysis due to their congested structures as well as the associated difficulties in controlling chemo- and stereoselectivity. In this work, we have explored asymmetric aminocatalysis with a-substituted beta-ketoesters. A simple chiral primary amine catalyst was identified to enable unprecedentedly effective catalysis of beta-ketoesters in alpha-hydrazination and Robinson annulation reaction with good yields and high enantioselectivities. Stoichiometric experiments with preformed enamine ester intermediates revealed their enamine-catalytic nature as well as the critical roles of acidic additives in facilitating catalytic turnovers and in tuning the chemo- and stereoselectivity. With the identical catalytic system, the two reactions demonstrated opposite chiral inductions in terms of the absolute configurations of the newly formed stereogenic centers. Investigations into this intriguing issue by DFT have revealed divergent stereocontrol modes. For a-hydrazination, H-bonding-directed facial attack determines the stereoselectivity, whereas a steric model is applied to the Robinson annulation where dual activations of both beta-ketoester and vinyl ketone/aldehyde are involved |
| 源URL | [http://ir.iccas.ac.cn/handle/121111/38588]  |
| 专题 | 化学研究所_其它 |
| 推荐引用方式 GB/T 7714 | Ouyang, Guang-Hui,He, Yan-Mei,Fan, Qing-Hua. Podand-Based Dimeric Chromium(III)-Salen Complex for Asymmetric Henry Reaction: Cooperative Catalysis Promoted by Complexation of Alkali Metal Ions[J]. CHEMISTRY-A EUROPEAN JOURNAL,DEC ,20(50):16454-16457. |
| APA | Ouyang, Guang-Hui,He, Yan-Mei,&Fan, Qing-Hua.(DEC ).Podand-Based Dimeric Chromium(III)-Salen Complex for Asymmetric Henry Reaction: Cooperative Catalysis Promoted by Complexation of Alkali Metal Ions.CHEMISTRY-A EUROPEAN JOURNAL,20(50),16454-16457. |
| MLA | Ouyang, Guang-Hui,et al."Podand-Based Dimeric Chromium(III)-Salen Complex for Asymmetric Henry Reaction: Cooperative Catalysis Promoted by Complexation of Alkali Metal Ions".CHEMISTRY-A EUROPEAN JOURNAL 20.50(DEC ):16454-16457. |
入库方式： OAI收割
来源：化学研究所
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