Department of Chemistry "Ugo Schiff", University of Florence, Via della Lastruccia, 3-13, 50019 Sesto Fiorentino, Italy.
Department of Inorganic and Organic Chemistry, University of Jaén, 23071 Jaén, Spain.
Molecules. 2019 Jul 26;24(15):2714. doi: 10.3390/molecules24152714.
A new G-(HL)-Pd heterogeneous catalyst has been prepared via a self-assembly process consisting in the spontaneous adsorption, in water at room temperature, of a macrocyclic HL ligand on graphene (G) (G + HL = G-(HL)), followed by decoration of the macrocycle with Pd ions (G-(HL) + Pd = G-(HL)-Pd) under the same mild conditions. This supramolecular approach is a sustainable (green) procedure that preserves the special characteristics of graphene and furnishes an efficient catalyst for the Cu-free Sonogashira cross coupling reaction between iodobenzene and phenylacetylene. Indeed, G-(HL)-Pd shows an excellent conversion (90%) of reactants into diphenylacetylene under mild conditions (50 °C, water, aerobic atmosphere, 14 h). The catalyst proved to be reusable for at least four cycles, although decreasing yields down to 50% were observed.
一种新型的 G-(HL)-Pd 多相催化剂是通过自组装过程制备的，该过程包括在室温下将大环 HL 配体在水中自发吸附在石墨烯 (G) 上（G + HL = G-(HL)），然后在相同的温和条件下用 Pd 离子修饰大环（G-(HL) + Pd = G-(HL)-Pd）。这种超分子方法是一种可持续的（绿色）方法，保留了石墨烯的特殊性质，并提供了一种高效的催化剂，用于无铜 Sonogashira 交叉偶联反应碘化苯和苯乙炔。事实上，G-(HL)-Pd 在温和条件下（50°C、水、有氧气氛、14 小时）表现出优异的反应物转化率（90%）生成二苯乙炔。该催化剂至少可重复使用四次，但观察到产率下降至 50%。
