In the last few years, immobilization of homogeneous catalysts on various solid supports with the advantages of catalysts separation and recycling have been widely studied in many divergent areas of research.1 Therefore nano-sized catalysts can serve as an efficient bridge gap between homogeneous and heterogeneous catalysts.2 Among different nanoparticles, mesoporpus silica, especially MCM-41, is commonly employed as a heterogeneous support for the immobilization of homogeneous catalysts. Compared to traditional silica materials, mesoporous silica have several advantages, such as thermal and mechanical stability (up to 900 ºC), large specific surface area for catalyst loading (up to 900 m2/g), high dispersion of the active phases, non-toxic content, ease of surface modification and tunable pore size.3 Its large pore size allows passage of large molecules such as metal complexes through the pores to reach to the surface of the channel. Additionally, the supported catalyst on mesoporous silica can be reused for several runs without significant loss of its catalytic efficiency. Herein, we report a new system for the C-C coupling reaction using sodium tetraphenyl borate or phenylboronic acid in the presence of Pd-complex@MCM-41 as mesoporous catalyst (Scheme 1).
