在膦树状大分子配体存在下,使用氢在四氢呋喃中还原双(乙酰丙酮)钯[Pd(acac)2 ],形成树状大分子稳定的钯纳米颗粒。通过TEM,31 P NMR和31表征所得的Pd纳米颗粒P MAS NMR。结果表明,树枝状膦配体被氧化为氧化膦。这些树状聚合物稳定的Pd纳米颗粒被证明是Suzuki和Stille偶联反应和氢化的有效催化剂。树状楔用作稳定剂以防止纳米颗粒聚集,并且用作促进Pd催化剂的分离和/或再循环的载体。在铃木偶联反应的情况下,与常用的均相催化剂四(三苯基膦)钯[Pd(PPh 3)4相比,这些Pd纳米颗粒显示出高催化效率(TON高达65,000)和空气稳定性。]。此外,从庞大的树突状基质获得的结果表明,Pd纳米颗粒可能充当催化活性物质的储存库,并且该反应实际上是由从水中浸出的可溶性Pd(0)和/或Pd(II)物质催化的。纳米颗粒表面。
Phosphine Dendrimer-Stabilized Palladium Nanoparticles, a Highly Active and Recyclable Catalyst for the Suzuki−Miyaura Reaction and Hydrogenation
作者:Lei Wu、Bao-Lin Li、Yi-Yong Huang、Hai-Feng Zhou、Yan-Mei He、Qing-Hua Fan
DOI:10.1021/ol0614424
日期:2006.8.1
[reaction: see text] Phosphinedendrimer-stabilized palladium nanoparticles were synthesized and found to be highly effective for Suzukicouplingreactions, affording good to excellent product yields, high turnover number (up to 65,000), and excellent reusability (up to 9 catalytic runs). Furthermore, these Pd nanoparticles are efficient and selective catalysts for hydrogenations.