Simple, efficient catalyst system for the palladium-catalyzed amination of aryl chlorides, bromides, and triflates
Simple, efficient catalyst system for the palladium-catalyzed amination of aryl chlorides, bromides, and triflates
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DOI：
10.1021/jo991699y
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发表时间：
2000-02-25
影响因子：
3.6
通讯作者：
Buchwald, SL
中科院分区：
文献类型：
--
作者：
Wolfe, JP;Tomori, H;Buchwald, SL
邻联苯基P（t-Bu）（2）（3）或邻联苯基PCy 2（4）负载的钯配合物是催化卤代芳烃和三氟甲磺酸酯胺化反应的有效催化剂。配体3的使用允许许多芳基氯、溴和三氟甲磺酸酯底物的室温催化胺化，而配体4对于官能化底物的胺化或无环仲胺的反应是有效的。催化剂在80-110 ℃下对于大量不同的底物组合表现良好，包括氯吡啶和官能化芳基卤化物和三氟甲磺酸酯，使用0.5-1.0摩尔% Pd;一些反应在低催化剂水平（0.05摩尔% Pd）下有效地进行。这些配体对于几乎所有先前已报道的与各种其它配体的底物组合都是有效的，并且它们代表了迄今为止报道的最普遍有效的催化剂体系。配体3和4是市售的空气稳定的结晶固体。它们的有效性被认为是由于促进氧化加成、Pd-N键形成和还原消除的空间和电子性质的组合。
Palladium complexes supported by (o-biphenyl)P(t-Bu)(2) (3) or (o-biphenyl)PCy2 (4) are efficient catalysts for the catalytic amination of a wide variety of aryl halides and triflates. Use of ligand 3 allows for the room-temperature catalytic amination of many aryl chloride, bromide, and triflate substrates, while ligand 4 is effective for the amination of functionalized substrates or reactions of acyclic secondary amines. The catalysts perform well for a large number of different substrate combinations at 80-110 degrees C, including chloropyridines and functionalized aryl halides and triflates using 0.5-1.0 mol % Pd; some reactions proceed efficiently at low catalyst levels (0.05 mol % Pd). These ligands are effective for almost all substrate combinations that have been previously reported with various other ligands, and they represent the most generally effective catalyst system reported to date. Ligands 3 and 4 are air-stable, crystalline solids that are commercially available. Their effectiveness is believed to be due to a combination of steric and electronic properties that promote oxidative addition, Pd-N bond formation, and reductive elimination.