Modified (NHC)Pd(allyl)Cl (NHC = <i>N</i>-Heterocyclic Carbene) Complexes for Room-Temperature Suzuki−Miyaura and Buchwald−Hartwig Reactions
作者:Nicolas Marion、Oscar Navarro、Jianguo Mei、Edwin D. Stevens、Natalie M. Scott、Steven P. Nolan
DOI:10.1021/ja057704z
日期:2006.3.1
activation step. This translates into higher catalytic activity in the Suzuki-Miyaura and Buchwald-Hartwig reactions, allowing for the coupling of unactivated aryl chlorides at room temperature in minutes. In the Suzuki-Miyaura reaction, aryl triflates, bromides, and chlorides react with boronic acids using very low catalyst loading. In the N-aryl amination reaction, a wide range of substrates has been
一系列 (NHC)Pd(R-烯丙基)Cl 配合物 [NHC: IPr = N,N'-bis(2,6-diisopropylphenyl)imidazol-2-ylidene, SIPr = N,N'-bis(2,6 -二异丙基苯基)-4,5-二氢咪唑-2-亚基;R = H, Me, gem-Me2, Ph] 已被合成并充分表征。与 (NHC)Pd(烯丙基)Cl 相比,烯丙基支架末端位置的取代有利于更容易的活化步骤。这在 Suzuki-Miyaura 和 Buchwald-Hartwig 反应中转化为更高的催化活性,允许在室温下在几分钟内偶联未活化的芳基氯化物。在 Suzuki-Miyaura 反应中,芳基三氟甲磺酸酯、溴化物和氯化物使用非常低的催化剂负载量与硼酸反应。在N-芳基胺化反应中,广泛的底物得到了有效偶联;伯-, 仲-, 烷基-, 或芳基胺与未活化、中性和活化的芳基氯化物和溴化物以