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首页> 外文期刊>The journal of physical chemistry, A. Molecules, spectroscopy, kinetics, environment, & general theory >Asymmetric Hydroformylation Catalyzed by RhH(CO)_2[(R,S)?Yanphos]: Mechanism and Origin of Enantioselectivity
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Asymmetric Hydroformylation Catalyzed by RhH(CO)_2[(R,S)?Yanphos]: Mechanism and Origin of Enantioselectivity

机译：RhH（CO）_2 [（R，S）？Yanphos]催化的不对称羰基化反应：对映选择性的机理和起源

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Asymmetric hydroformylation (AHF) catalyzed by transition metal (TM) complexes bearing chiral phosphorus ligands is one of the most powerful synthetic ways that could provide chiral aldehydes directly from alkenes and syngas in one step. Experiments have proved the efficiency of Rh catalyst with hybrid phosphorus ligands owning two different phosphorus moieties in AHF. Herein the origin of enantioselectivity of AHF catalyzed by RhH-(CO)2[(R,S)-Yanphos] was studied at M06/BSI level using the density functional theory (DFT) method to unveil a fundamental understanding on factors contributing to the efficiency in AHF. The alkene insertion step is supposed to be the chirality-determining step in the whole catalytic cycle of the Rh-Yanphos system. Four possible pathways of styrene (Sub1) insertion step (pathways R1, S1, R2, and S2) were discussed; the calculated results indicate that pathways R1 and S2 are proposed to be two dominant alkene insertion pathways and that styrene tends to adopt apical coordination mode (A mode) to Rh center in pathways R1 and S2 compared to equatorial coordination mode (E mode) in pathways R2 and S1. The enantioselectivity of AHFs of ten alkene substrates (CH_2=CH-R, RPh, C(=O)OCH_3, Ph-(p)-Me, Ph-(p)-OMe, Ph-(p)-~iBu, Ph-(p)-F, Ph-(p)-Cl, Ph-(o)-F, OC(=O)-Ph and O-Ph, corresponding alkenes are abbreviated as Sub1 to Sub10, respectively) were also investigated. The predicted chiralities agree well with experimental results. The present work suggests that the relative stabilities of coordination modes (A/E mode) of alkene to 2 (RhH(CO)[(R,S)-Yanphos]) might be of importance in the enantioselectivity of AHF catalyzed by Rh-Yanphos.
机译：带有手性磷配体的过渡金属（TM）配合物催化的不对称加氢甲酰化（AHF）是最有效的合成方法之一，可以一步一步直接从烯烃和合成气中提供手性醛。实验证明了在AHF中具有两个不同磷部分的杂化磷配体的Rh催化剂的效率。本文在M06 / BSI级别上使用密度泛函理论（DFT）方法研究了RhH-（CO）2 [（R，S）-Yanphos]催化的AHF的对映选择性的起源，以揭示对促成AHF的因素的基本理解。 AHF中的效率。在Rh-Yanphos体系的整个催化循环中，烯烃插入步骤被认为是决定手性的步骤。讨论了苯乙烯（Sub1）插入步骤的四个可能途径（途径R1，S1，R2和S2）。计算结果表明，途径R1和S2被认为是两个主要的烯烃插入途径，与途径中的赤道配位模式（E模式）相比，苯乙烯倾向于在途径R1和S2中向Rh中心采用顶配位模式（A模式）。 R2和S1。十种烯烃底物（CH_2 = CH-R，RPh，C（= O）OCH_3，Ph-（p）-Me，Ph-（p）-OMe，Ph-（p）-iBu）的AHF对映选择性，Ph-（p）-F，Ph-（p）-Cl，Ph-（o）-F，OC（= O）-Ph和O-Ph，相应的烯烃分别缩写为Sub1至Sub10）调查。预测的手性与实验结果非常吻合。目前的工作表明烯烃对2（RhH（CO）[（R，S）-Yanphos]的配位模式（A / E模式）的相对稳定性可能对Rh-Yanphos催化的AHF的对映选择性很重要。 。

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