Balogh Janos, Hlil Antsar Rih, El-Zoghbi Ibrahim, Rafique Muhammad Ghufran, Chouikhi Dalila, Al-Hashimi Mohammed, Bazzi Hassan S
Department of Chemistry, Texas A&M University at Qatar, P. O. Box 23874, Doha, Qatar.
Macromol Rapid Commun. 2017 Aug;38(15). doi: 10.1002/marc.201700214. Epub 2017 Jun 19.
This paper reports the efficient synthesis of the first class of polyisobutylene(PIB)-supported palladium-PEPPSI precatalyst (PEPPSI = pyridine-enhanced precatalyst preparation, stabilization, and initiation). The new complexes are employed in Buchwald-Hartwig amination of aryl chlorides and are found to be reasonably active in the titled cross-coupling reaction. The supported catalysts are tested in polar (1,4-dioxane and 1,2-dimethoxyethane) as well as in aliphatic reaction media (toluene and n-heptane) and display superior activity in the highly lipophilic solvent (n-heptane). The catalytic efficacy of PIB-Pd-PEPPSI precatalyst is measured to be comparable to its nonsupported analog. Pd-leaching is determined by inductively coupled plasma mass spectrometry (ICP-MS) after a simple liquid/liquid extraction and is found to be 2 ppb in the product phase, translating into a recovery of ≈99.8% of the palladium.
本文报道了第一类聚异丁烯（PIB）负载的钯-PEPPSI预催化剂（PEPPSI = 吡啶增强的预催化剂制备、稳定化及引发）的高效合成。这些新型配合物用于芳基氯的布赫瓦尔德-哈特维希胺化反应，发现在标题所示的交叉偶联反应中具有一定活性。负载型催化剂在极性（1,4-二氧六环和1,2-二甲氧基乙烷）以及脂肪族反应介质（甲苯和正庚烷）中进行了测试，在高亲脂性溶剂（正庚烷）中表现出优异的活性。PIB-Pd-PEPPSI预催化剂的催化效能经测定与其非负载类似物相当。通过简单的液/液萃取后，用电感耦合等离子体质谱法（ICP-MS）测定钯的浸出情况，发现在产物相中为2 ppb，这意味着钯的回收率约为99.8%。
