Experimental and density functional theory studies on hydroxymethylation of phenylboronic acids with paraformaldehyde over a Rh PPh3 catalyst
Experimental and density functional theory studies on hydroxymethylation of phenylboronic acids with paraformaldehyde over a Rh PPh3 catalyst
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Rh-PPh3 催化剂上多聚甲醛对苯基硼酸羟甲基化的实验和密度泛函理论研究
DOI：
10.1002/aoc.6104
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发表时间：
2020
影响因子：
3.9
通讯作者：
Zhao-Tie Liu
中科院分区：
文献类型：
--
作者：
Kuan Wang;Jie Lan;Zhen-Hong He;Zhe Cao;Weitao Wang;Yang Yang;Zhao-Tie Liu
苄醇类化合物在有机合成和医药领域有着广泛的应用，因此苄醇类化合物的合成至关重要。本文采用简单的铑-PPh 3催化剂和无机碱（NaOH）相结合，通过苯硼酸（PBAs）和多聚甲醛的羟甲基化反应，高效合成了苯甲酸。结果表明，该方法具有较好的普适性，得到了CH 3-、CH 3 O-、Cl-、Br-等多种结构的BA，产率中等至较高。密度泛函理论（DFT）计算提出Hayashi型芳基化反应机理包括PBA与Rh（OH）（PPh 3）2催化剂的芳基化反应生成Rh（I）键合的芳基中间体和Rh（I）键合的芳基中间体与甲醛的水解反应生成BA产物（速率决定步骤）。该路线为多聚甲醛的合成提供了一种有价值的直接方法，扩大了多聚甲醛的应用范围。
The synthesis of benzyl alcohols (BAs) is highly vital for their wide applications in organic synthesis and pharmaceuticals. Herein, BAs was efficiently synthesized via hydroxymethylation of phenylboronic acids (PBAs) and paraformaldehyde over a simple RhPPh3catalyst combined with an inorganic base (NaOH). A variety of BAs with the groups of CH3−, CH3O−, Cl−, Br−, and so on were obtained with moderate to good yields, indicating that the protocol had a good universality. Density functional theory (DFT) calculations proposed the Hayashi‐type arylation mechanism involved the arylation step of PBA and Rh(OH)(PPh3)2catalyst to form Rh(I)‐bound aryl intermediates and the hydrolysis step of Rh(I)‐bound aryl intermediates and HCHO to generate BA product (the rate‐determining step). The present route provides a valuable and direct method for the synthesis of BAs and expands the application range of paraformaldehyde.