Sustainable ligand-free, Palladium-catalyzed Suzuki-Miyaura reactions in water: insights into the role of base
Sustainable ligand-free, Palladium-catalyzed Suzuki-Miyaura reactions in water: insights into the role of base
复制标题
水中可持续的无配体、钯催化的 Suzuki-Miyaura 反应：深入了解碱的作用
DOI：
10.1002/cssc.201902853
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发表时间：
2019
期刊：
影响因子：
8.4
通讯作者：
Gao Ziwei
中科院分区：
文献类型：
--
作者：
Wang Yanyan;Liu Yuanyuan;Zhang Wei-qiang;Sun Huaming;Zhang Kan;Jian Yajun;Gu Quan;Zhang Guofang;Li Jiyang;Gao Ziwei
开发了一种简单有效的系统，用于在温和条件下在水中进行无配体 Pd 催化的 Suzuki-Miyaura 反应。发现长链氢氧化季铵是非常合适的碱。这种无配体 Pd 催化的 Suzuki-Miyaura 反应显示出在水中的耐久性得到改善，并且 Pd 负载量降低至 ppm 水平。碱除了在催化过程中充当碱外，还可以稳定活性钯物质。在强碱催化体系中，可溶性活性钯离子表现出抗还原特性，防止了钯物质的聚集和失活。通过简单过滤分离产物后，整个催化体系可循环利用。本文描述的水相容性和空气稳定性的有效催化方案代表了铃木-宫浦偶联中有吸引力的绿色合成进展。
A simple and efficient system was developed for the ligand‐free Pd‐catalyzed Suzuki–Miyaura reaction in water under mild conditions. Quaternary ammonium hydroxides with long chains were found to be very suitable bases. This ligand‐free Pd‐catalyzed Suzuki–Miyaura reaction showed improved durability in water with Pd loadings decreased to ppm level. Bases were shown to stabilize active palladium species in addition to acting as a base during the catalytic process. In the catalytic system with a strong base, the soluble active PdIIion exhibited anti‐reduction properties, which prevented aggregation and deactivation of Pd species. The entire catalytic system could be recycled after separating the product by simple filtration. The water‐compatible and air‐stable effective catalytic protocol described herein represents an attractive and green synthetic advance in Suzuki–Miyaura couplings.