Functionalized Magnetic Mesoporous Silica Nanoparticle‐Supported Palladium Catalysts for Carbonylative Sonogashira Coupling Reactions of Aryl Iodides

Abstract

Magnetic mesoporous silica nanoparticles (MMSN) were prepared and used as a support for palladium catalysts. MMSN with a surface area of 1909 m2 g−1 were synthesized by a nanoemulsification process involving the dispersion of hydrophobic magnetite nanoparticles in chloroform in the presence of cetyltrimethylammonium bromide, followed by the addition of tetraethoxysilane and its polycondensation by a sol–gel route. The MMSN were modified with phosphine and N‐heterocyclic carbene‐based ligands, which provided coordination sites for conjugation with a palladium catalyst. These modified particles were fully characterized and employed as catalyst nanosupports. The palladium catalyst was immobilized on the surface and within the pores of MMSN and applied in copper‐free carbonylative Sonogashira coupling reactions of aryl iodides with terminal alkynes.

Palladium supported on bis(indolyl)methane functionalized magnetite nanoparticles as an efficient catalyst for copper-free Sonogashira-Hagihara reaction

“…We have recently introduced two novel and efficient phosphane-free magnetic nanoparticles which supported palladium catalysts for Suzuki-Miyaura coupling reaction in water [40][41]. However, to date, a few magnetite nanoparticles supported palladium catalysts have been prepared and successfully used in the Sonogashira-Hagihara coupling reaction [42][43][44][45][46][47][48][49][50].…”

Recent Advances in the Synthesis, Surface Modifications and Applications of Core‐Shell Magnetic Mesoporous Silica Nanospheres

“…Core-shell Mag-MSNs have been employed as catalysts for various types of reactions, including asymmetric hydrogenation, [132] asymmetric Henry reaction, [133] Olefin epoxidation, [134] asymmetric dihydroxylation, [135] Suzuki-Miyaura reaction, [136] Heck, [137] and Sonogashira coupling reactions. [138] The first work using core-shell Mag-MSNs as the organic catalyst was published by Zhao's group. [139] They prepared multi-functional core-shell Mag-MSNs with the reactive gold nanoparticle as the transition layer.…”

“…Because the core‐shell Mag‐MSNs has a high surface area, it can achieve a high dispersion of catalytic active sites and easy magnetic separation, so it is very suitable as a carrier for organic catalysis. Core‐shell Mag‐MSNs have been employed as catalysts for various types of reactions, including asymmetric hydrogenation, asymmetric Henry reaction, Olefin epoxidation, asymmetric dihydroxylation, Suzuki‐Miyaura reaction, Heck, and Sonogashira coupling reactions . The first work using core‐shell Mag‐MSNs as the organic catalyst was published by Zhao's group .…”

Silica‐Supported Molecular Catalysts for Tandem Reactions

“…The second example using aS iO 2 -supported organopalladium catalystw as reported by the Abu-Reziq group. [60] They utilized magnetic mesoporous silica nanoparticles (MMSNs)a sa support to construct three mesoporous silica-supportedo rganopalladium catalysts( (PPh 2 ) 2 Pd/MMSNs, NHCPd/MMSNs and NiXantphosPd/MMSNs) ( Figure 5). In this case, the magnetic mesoporoussilica nanoparticles support was prepared through an anoemulsification process.…”