Highly reactive, general and long-lived catalysts for palladium-catalyzed amination of heteroaryl and aryl chlorides, bromides, and iodides: Scope and structure-activity relationships
Highly reactive, general and long-lived catalysts for palladium-catalyzed amination of heteroaryl and aryl chlorides, bromides, and iodides: Scope and structure-activity relationships
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DOI：
10.1021/ja077074w
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发表时间：
2008-05-21
影响因子：
15
通讯作者：
Hartwig, John F.
中科院分区：
文献类型：
--
作者：
Shen, Qilong;Ogata, Tokutaro;Hartwig, John F.
我们描述了一个系统的研究范围和配体结构和活性之间的关系，为一个高效的和选择性的一类催化剂含有空间位阻螯合烷基膦的杂芳基和芳基的氯化物，溴化物和碘化物的胺化。在该催化剂存在下，芳基和杂芳基氯化物、溴化物和碘化物与许多伯胺以高产率与百万分之一量的钯前体和配体反应。伯胺与杂芳基和芳基氯化物、溴化物和碘化物的许多反应在0.0005-0.05摩尔%催化剂下发生完成。这种催化剂在这些负载量下用于伯胺偶联的反应性的比较是与由受阻单膦和卡宾产生的催化剂进行的，并且这些数据说明了螯合的益处。对最具活性的催化剂的结构变体的研究表明，双齿结构中的刚性骨架、强电子供体和严重的位阻都有助于其高反应性。因此，这些配合物构成了用于芳基卤化物胺化的第四代催化剂，其活性补充了基于单膦和卡宾的催化剂。
We describe a systematic study of the scope and relationship between ligand structure and activity for a highly efficient and selective class of catalysts containing sterically hindered chelating alkylphosphines for the amination of heteroaryl and aryl chlorides, bromides, and iodides. In the presence of this catalyst, aryl and heteroaryl chlorides, bromides, and iodides react with many primary amines in high yields with part-per-million quantities of palladium precursor and ligand. Many reactions of primary amines with both heteroaryl and aryl chlorides, bromides, and iodides occur to completion with 0.0005-0.05 mol % catalyst. A comparison of the reactivity of this catalyst for the coupling of primary amines at these loadings is made with catalysts generated from hindered monophosphines and carbenes, and these data illustrate the benefits of chelation. Studies on structural variants of the most active catalyst indicate that a rigid backbone in the bidentate structure, strong electron donation, and severe hindrance all contribute to its high reactivity. Thus, these complexes constitute a fourth-generation catalyst for the amination of aryl halides, whose activity complements catalysts based on monophosphines and carbenes.