Department of Chemistry, University of California, Berkeley, California 94720, USA.
Nat Chem. 2010 Jan;2(1):36-41. doi: 10.1038/nchem.468. Epub 2009 Nov 29.
A continuing goal in catalysis is to unite the advantages of homogeneous and heterogeneous catalytic processes. To this end, nanoparticles represent a new frontier in heterogeneous catalysis, where this unification can also be supplemented by the ability to obtain new or divergent reactivity and selectivity. We report a novel method for applying heterogeneous catalysts to known homogeneous catalytic reactions through the design and synthesis of electrophilic platinum nanoparticles. These nanoparticles are selectively oxidized by the hypervalent iodine species PhICl(2), and catalyse a range of π-bond activation reactions previously only catalysed through homogeneous processes. Multiple experimental methods are used to unambiguously verify the heterogeneity of the catalytic process. The discovery of treatments for nanoparticles that induce the desired homogeneous catalytic activity should lead to the further development of reactions previously inaccessible in heterogeneous catalysis. Furthermore, a size and capping agent study revealed that Pt PAMAM dendrimer-capped nanoparticles demonstrate superior activity and recyclability compared with larger, polymer-capped analogues.
在催化领域中，一个持续的目标是结合均相催化和多相催化过程的优势。为此，纳米粒子代表了多相催化的一个新前沿，通过这种统一，还可以通过获得新的或不同的反应性和选择性来补充。我们通过设计和合成亲电铂纳米粒子，报道了一种将多相催化剂应用于已知均相催化反应的新方法。这些纳米粒子可以被高价碘物种 PhICl(2)选择性氧化，并催化一系列以前只能通过均相过程催化的π键活化反应。使用多种实验方法来明确验证催化过程的多相性。对于可以诱导所需均相催化活性的纳米粒子的处理方法的发现，应该会导致进一步发展以前在多相催化中无法进行的反应。此外，尺寸和封端剂研究表明，与较大的聚合物封端类似物相比，Pt PAMAM 树枝状大分子封端的纳米粒子具有更高的活性和可回收性。
