Air-Stable Pd(R-allyl)LCl (L = Q-Phos, P(t-Bu)3, etc.) Systems for C-C/N Couplings: Insight into the Structure Activity Relationship and Catalyst Activation Pathway
Air-Stable Pd(R-allyl)LCl (L = Q-Phos, P(t-Bu)3, etc.) Systems for C-C/N Couplings: Insight into the Structure Activity Relationship and Catalyst Activation Pathway
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DOI：
10.1021/jo2013324
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发表时间：
2011-10-07
影响因子：
3.6
通讯作者：
Colacot, Thomas J.
中科院分区：
文献类型：
--
作者：
Seechurn, Carin C. C. Johansson;Parisel, Sebastien L.;Colacot, Thomas J.
合成了一系列Pd（R-烯丙基）LCl配合物[R = H，1-Me，1-Ph，1-gem-Me-2，2-Me; L = Q-Phos，P（t-Bu）（3），P（t-Bu）（2）-（p-NMe_2C_6 H_4），P（t-Bu）（2）Np]，并对它们在Buchwald Hartwig胺化反应中的应用进行了详细的评价，同时对Suzuki偶联反应和α-芳基化反应进行了初步的研究。Pd（crotyl）Q：PhosCl（9）是一种上级催化剂，在4-溴苯甲醚与N-甲基苯胺或4-叔丁基苯硼酸的模型偶联反应中优于其他QPhos基催化剂和已报道的原位体系.预催化剂9也比带有P（t-Bu）（2）（p-NMe 2C 6 H4）配体的催化剂表现更好;然而，其与带有P（t-Bu）（3）或P（t-Bu）（2）Np配体的新巴豆基催化剂相当。在1-四氢萘酮的α-芳基化反应中，Pd（allyl）P（t-Bu）（2）（p-NMe_2C_6 H_4）Cl（15）是最好的催化剂。巴豆基配合物的C-N键形成反应中的烯丙基衍生物相比，相对较高的活性的原因进行了研究，使用X-射线晶体学结合NMR光谱研究。
A series of Pd(R-allyl)LCl complexes [R = H, 1-Me, 1-Ph, 1-gem-Me-2, 2-Me; L = Q-Phos, P(t-Bu)(3), P(t-Bu)(2)-(p-NMe2C6H4), P(t-Bu)(2)Np] have been synthesized and evaluated in the Buchwald Hartwig aminations in detail, in addition to the preliminary studies on Suzuki coupling and a-arylation reactions. Pd(crotyl)Q:PhosCl (9) was found to be a superior catalyst to the other QPhos-based catalysts, and the reported in situ systems, in model coupling reactions involving 4-bromoanisole substrate with either N-methylaniline or 4-tert-butylbenzeneboronic acid. Precatalyst 9 also performed better than the catalysts bearing P(t-Bu)(2)(p-NMe2C6H4) ligand; however, it is comparable to the new crotyl catalysts bearing P(t-Bu)(3) or P(t-Bu)(2)Np ligands. In alpha-arylation of a biologically important model substrate, 1-tetralone, Pd(allyl)P(t-Bu)(2)(p-NMe2C6H4)Cl (15) was found to be the best catalyst. The reason for the relatively higher activity of the crotyl complexes in comparison to the allyl derivatives in C-N bond formation reactions was investigated using X-ray crystallography in conjunction with NMR spectroscopic studies.