Department of Chemistry, Dalhousie University, Nova Scotia B3H 4J3, Canada.
Chemistry. 2010 Feb 8;16(6):1983-91. doi: 10.1002/chem.200902316.
The syntheses of 2-(di-tert-butylphosphino)-N,N-dimethylaniline (L1, 71%) and 2-(di-1-adamantylphosphino)-N,N-dimethylaniline (L2, 74 %), and their application in Buchwald-Hartwig amination, are reported. In combination with Pd(allyl)Cl or Pd(cinnamyl)Cl, these structurally simple and air-stable P,N ligands enable the cross-coupling of aryl and heteroaryl chlorides, including those bearing as substituents enolizable ketones, ethers, esters, carboxylic acids, phenols, alcohols, olefins, amides, and halogens, to a diverse range of amine and related substrates that includes primary alkyl- and arylamines, cyclic and acyclic secondary amines, N-H imines, hydrazones, lithium amide, and ammonia. In many cases, the reactions can be performed at low catalyst loadings (0.5-0.02 mol % Pd) with excellent functional group tolerance and chemoselectivity. Examples of cross-coupling reactions involving 1,4-bromochlorobenzene and iodobenzene are also reported. Under similar conditions, inferior catalytic performance was achieved when using Pd(OAc)(2), PdCl(2), [PdCl(2)(cod)] (cod = 1,5-cyclooctadiene), [PdCl(2)(MeCN)(2)], or [Pd(2)(dba)(3)] (dba = dibenzylideneacetone) in combination with L1 or L2, or by use of Pd(allyl)Cl or Pd(cinnamyl)Cl with variants of L1 and L2 bearing less basic or less sterically demanding substituents on phosphorus or lacking an ortho-dimethylamino fragment. Given current limitations associated with established ligand classes with regard to maintaining high activity across the diverse possible range of C-N coupling applications, L1 and L2 represent unusually versatile ligand systems for the cross-coupling of aryl chlorides and amines.
报告了 2-(二-叔丁基膦基)-N,N-二甲基苯胺（L1，71%）和 2-(二-1-金刚烷基膦基)-N,N-二甲基苯胺（L2，74%）的合成及其在 Buchwald-Hartwig 胺化反应中的应用。这些结构简单、空气稳定的 P,N 配体与Pd(allyl)Cl或Pd(cinnamyl)Cl结合，可使芳基和杂芳基氯化物与各种胺和相关底物发生交叉偶联，包括带有烯醇化酮、醚、酯、羧酸、酚、醇、烯烃、酰胺和卤素等取代基的底物，包括伯烷基和芳基胺、环状和无环仲胺、N-H 亚胺、腙、锂酰胺和氨。在许多情况下，反应可以在低催化剂负载（0.5-0.02 mol %Pd）下进行，具有出色的官能团耐受性和化学选择性。还报告了涉及 1,4-二氯苯和碘苯的交叉偶联反应的实例。在类似条件下，使用 Pd(OAc)(2)、PdCl(2)、[PdCl(2)(cod)]（cod = 1,5-环辛二烯）、[PdCl(2)(MeCN)(2)]或[Pd(2)(dba)(3)]（dba = 二苄叉丙酮）与 L1 或 L2 结合，或使用Pd(allyl)Cl或Pd(cinnamyl)Cl与 L1 和 L2 的变体结合，这些变体在磷上具有碱性较低或空间位阻较小的取代基或缺少邻二甲氨基片段时，催化性能较差。鉴于当前与建立配体类相关的限制，在各种可能的 C-N 偶联应用中保持高活性，L1 和 L2 代表了用于芳基氯化物和胺的交叉偶联的非常通用的配体系统。
