Effect of Aryl Ligand Identity on Catalytic Performance of Trineopentylphosphine Arylpalladium Complexes in N -Arylation Reactions
Effect of Aryl Ligand Identity on Catalytic Performance of Trineopentylphosphine Arylpalladium Complexes in N -Arylation Reactions
复制标题
芳基配体特性对三戊基膦芳基钯配合物 N-芳基化反应催化性能的影响
DOI：
10.1021/acs.organomet.0c00140
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发表时间：
2020
期刊：
影响因子：
2.8
通讯作者：
Shaughnessy, Kevin H.
中科院分区：
文献类型：
--
作者：
Hu, Huaiyuan;Burlas, Corrie E.;Curley, Sabrina J.;Gruchala, Tomasz;Qu, Fengrui;Shaughnessy, Kevin H.
合成了一系列空气稳定的[(Np3P)Pd(Ar)Br]2(Np=新戊基)和(Np3P)Pd(Ar)(胺)BR(胺=吗啉和异丁胺)配合物，并将其作为空间要求较高的芳基溴化物与苯胺类化合物偶联的预催化剂。这些络合物比Pd2(Dba)3和PNp3原位生成的催化剂具有更高的活性。芳基对钯的空间需求增加与催化剂活性的提高相关。与Pd2(Dba)3/PNp3催化剂相比，[(Np3P)Pd(2，6-Me2C6H3)Br2]2催化的反应在较低的温度下反应效率较高或相近。与[(Np3P)Pd(Ar)Br2]2络合物相比，胺加合物的反应速率和产物转化率较低。胺加合物的低活性似乎是由于生成催化活性的LPd(0)物种的缓慢的碱促进还原消除所致。
A series of air-stable [(Np3P)Pd(Ar)Br]2(Np = neopentyl) and (Np3P)Pd(Ar)(amine)Br complexes (amine = morpholine and isobutylamine) have been prepared and tested as precatalysts for the coupling of sterically demanding aryl bromides and aniline derivatives. The complexes are more active than the catalyst generated in situ from Pd2(dba)3and PNp3. Increasing steric demand of the aryl group on palladium correlates with increased catalyst activity. Reactions catalyzed by [(Np3P)Pd(2,6-Me2C6H3)Br]2occur efficiently at lower temperatures and with similar or higher yields than those using Pd2(dba)3/PNp3. The amine adducts give lower reaction rates and conversion to product than the [(Np3P)Pd(Ar)Br]2complexes. The lower activity of the amine adducts appears to result from slow base-promoted reductive elimination to generate the catalytically active LPd(0) species.