二(三苯基膦)二钯(0)/三叔丁基膦催化芳基氯的布赫瓦尔德-哈特维希胺化反应的范围和局限性

Scope and limitations of Pd2(dba)3/P(i-BuNCH2CH2)3N-catalyzed Buchwald-Hartwig amination reactions of aryl chlorides.

作者信息

Urgaonkar Sameer, Verkade John G

机构信息

Department of Chemistry, Gilman Hall, Iowa State University, Ames, Iowa 50011-3111, USA.

出版信息

J Org Chem. 2004 Dec 24;69(26):9135-42. doi: 10.1021/jo048716q.

DOI:10.1021/jo048716q

PMID:15609947

Abstract

Proazaphosphatrane ligands in combination with Pd(2)(dba)(3) generate highly active catalysts for Buchwald-Hartwig amination of aryl chlorides. In particular, commercially available P(i-BuNCH(2)CH(2))(3)N is a highly general and efficient ligand, allowing the coupling of an electronically diverse set of aryl chlorides, including chloropyridines, with a wide variety of amines using 1 mol % of Pd at 100 degrees C. Either a 1:1 or 2:1 ratio of ligand to Pd was found to be effective. This catalyst system performs exceptionally well for sterically hindered substrates, even with only 0.25 mol % of Pd. It is shown that NaOH can also be used as the base (instead of NaO-t-Bu) allowing functionalized substrates to participate in these reactions.

摘要

氮杂环卡宾膦配体与 Pd₂(dba)₃ 组合可生成用于芳基氯的 Buchwald-Hartwig 胺化反应的高活性催化剂。特别地，市售的 P(i-BuNCH₂CH₂)₃N 是一种通用性极高且高效的配体，在 100℃下使用 1 mol%的 Pd 时，能使包括氯吡啶在内的多种电子性质不同的芳基氯与多种胺发生偶联反应。发现配体与 Pd 的比例为 1:1 或 2:1 均有效。该催化体系对空间位阻较大的底物表现出色，即便仅使用 0.25 mol%的 Pd 也是如此。结果表明，NaOH 也可用作碱（代替叔丁醇钠），从而使官能化底物能够参与这些反应。