ABSTRACT

The reduction of functional groups has been thoroughly explored in organic synthesis. Nevertheless, most of the existing methodologies are based on conditions far from being environmentally friendly, which limits their usefulness. Here we report a green approach for the reduction of representative aryl functional groups using Eco-Pd catalysts. The Eco-Pd catalysts were prepared from palladium enriched vegetal filters that biosorbed palladium from an aquatic environment. The Eco-Pd catalysts were characterized by MP-AES XRPD and XPS, and used in the reductions of aryl halides, aryl aldehydes and nitroarenes in green conditions. A mixture of glycerol and n-butanol was used, as the solvent system and as the reducing reagent, in the presence of non-hazardous inorganic bases and without any ligands. Although Eco-Pd catalysis within this solvent system was homogeneous, we were able to recover and reuse the ecocatalyst to efficiently catalyze new reduction reactions.

摘要

在有机合成中已经彻底探索了官能团的还原。然而，大多数现有方法论都是基于远非环境友好的条件，这限制了它们的实用性。在这里，我们报告了一种使用Eco-Pd催化剂还原代表性芳基官能团的绿色方法。Eco-Pd催化剂由富含钯的植物滤池制备而成，该滤池可从水生环境中生物吸附钯。Eco-Pd催化剂通过MP-AES XRPD和XPS进行了表征，并用于在绿色条件下还原芳基卤化物，芳基醛和硝基芳烃。甘油和正丙醇的混合物在无害无机碱存在且没有任何配体的情况下，使用-丁醇作为溶剂体系和还原剂。尽管此溶剂系统中的Eco-Pd催化作用是均匀的，但我们仍能够回收和再利用该生态催化剂，以有效地催化新的还原反应。