Long-Distance Chirality Transfer from P-Ligand to Prochiral Dihydrosilanes via Pd(II) Aryl Iodide Complex in Pd-Catalyzed Silylation of Aryl Iodide: A DFT Study.
Long-Distance Chirality Transfer from P-Ligand to Prochiral Dihydrosilanes via Pd(II) Aryl Iodide Complex in Pd-Catalyzed Silylation of Aryl Iodide: A DFT Study.
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DOI：
10.1021/acs.joc.0c00202
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发表时间：
2020-05
期刊：
影响因子：
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通讯作者：
Jingjing Yang;Zheng Xu;Yi-Xue Nie;Si-Qi Lu;Jin Zhang;Li‐Wen Xu
中科院分区：
文献类型：
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作者：
Jingjing Yang;Zheng Xu;Yi-Xue Nie;Si-Qi Lu;Jin Zhang;Li‐Wen Xu
用杂化密度泛函理论(DFT)方法研究了在手性TADDOL衍生亚磷酰胺配体存在下，Pd催化二氢硅烷与芳基碘脱对称单芳基化反应的反应机理，以加深对立体选择性的理解。计算了有利反应途径的完整催化循环，该反应途径是由芳基碘与单寡化Pd0的氧化加成反应产生硅基化产物。密度泛函理论计算结果表明，Pd(II)芳基碘配合物的Pd-Ar键和前手性二氢硅烷的Si-H键之间的对映异构化是反应的速率决定步骤和对映体选择性决定步骤。根据过渡态的结构，发现配体的芳基、芳基碘和二氢硅烷之间的吸引芳基-芳基相互作用对前手性二氢硅烷的手性转移到不对称断裂的Si-H键起重要作用。
The mechanism of Pd-catalyzed desymmetric monoarylation of dihydrosilanes with aryl iodides in the presence of chiral TADDOL-derived phosphoramidite ligand towards a deeper understanding of the stereoselectivity has been investigated using hybrid density functional theory (DFT) methodology. The full catalytic cycle for the favorable reaction pathway, which is initiated by the oxidative addition of aryl iodide to monoligated Pd0 leading to the silylation product was calculated. The DFT calculation results indicate that the enantio-discriminating transmetalation between Pd-Ar bond of the Pd(II) aryl iodide complex and Si-H bond of the prochiral dihydrosilane was the rate-determining step as well as the enantioselective determining step. Based on the structure of the transition state, the attractive aryl-aryl interactions between the aryl group of ligand, aryl iodide and dihydrosilane were found to play important role for the chiral transfer-ence from the chiral ligand to asymmetric cleavage of the Si-H bond of the prochiral dihydrosilane.