|
Abstract
|
The application of catalysts to reduced systems toxicity, benign and renewable energy systems and reaction efficiency, make them as a central focus area for green chemistry research [1, 2]. In the last few years, immobilization of homogeneous catalysts on various solid supports with the advantage of catalysts separation and recycling has been widely studied in many divergent areas of research [3, 4]. However, immobilization of homogeneous catalysts usually, decreases the catalytic activity [5]. This drawback can be overcome using nanomaterials as ideal heterogeneous supports [6]. In supported catalysts, the catalytic behavior of the catalyst is strongly dependent on support properties. Among the various supported catalysts, particularly, alumina and silica supported reagents have advantages of low cost, ease of preparation and catalyst recycling [7, 8]. Also, among different mesoporpus silica, MCM-41 is commonly employed as a heterogeneous support for the immobilization of homogeneous catalysts [9]. Due to its unique properties such as high surface area, homogeneity of the pores, good thermal stability, tunable and accessible pores, MCM-41 has been a focus for several research areas like nanoscience [10], catalysis [11, 12] environmental purification [13], absorption [14] and drug delivery [15]. The nature of MCM-41 pore structure can be used to functionalize via reaction with alkoxysilyl compounds and then, incorporation of metal complexes into the channel walls [16-18]. Coupling reactions catalyzed by transition-metals are among the most important reactions in organic synthesis [19, 20] , since it is the most powerful tool for constructing a biaryl structure, which is found in many biologically active compounds, liquid crystals and EL materials [21]. Phenols and anilines are important building blocks for constructing natural products, pharmaceutical and medicinal compounds, as well as in polymers and materials [22]. Thus, the development of highly efficient method
|