Atwater Bruce, Chandrasoma Nalin, Mitchell David, Rodriguez Michael J, Organ Michael G
Department of Chemistry, York University, 4700 Keele Street, Toronto M3J1P3, Ontario, Canada.
Lilly Research Laboratories, Indianapolis, IN, 46285, USA.
Chemistry. 2016 Oct 4;22(41):14531-4. doi: 10.1002/chem.201603603. Epub 2016 Aug 24.
Dichloro1,3-bis(2,6-di-4-heptylphenyl)imidazol-2-ylidenepalladium(II) (Pd-PEPPSI-IHept(Cl) ), a new, very bulky yet flexible Pd-N-heterocyclic carbene (NHC) complex has been evaluated in the cross-coupling of secondary alkylzinc reactants with a wide variety of oxidative addition partners in high yields and excellent selectivity. The desired, direct reductive elimination branched products were obtained with no sign of migratory insertion across electron-rich and electron-poor aromatics and all forms of heteroaromatics (five and six membered). Impressively, there is no impact of substituents at the site of reductive elimination (i.e., ortho or even di-ortho), which has not yet been demonstrated by another catalyst system to date.
二氯1,3-双(2,6-二-4-庚基苯基)咪唑-2-亚基钯(II)（Pd-PEPPSI-IHept(Cl)），一种新型、体积庞大但灵活的钯-N-杂环卡宾（NHC）配合物，已在仲烷基锌反应物与多种氧化加成反应物的交叉偶联反应中进行了评估，反应产率高，选择性优异。得到了所需的直接还原消除支链产物，未观察到富电子和贫电子芳烃以及所有形式的杂芳烃（五元环和六元环）发生迁移插入的迹象。令人印象深刻的是，还原消除位点（即邻位甚至二邻位）上的取代基没有影响，迄今为止，尚未有其他催化体系能证明这一点。
