Mesoporous-silica-coated palladium-nanocubes as recyclable nanocatalyst in C–C-coupling reaction – a green approach

Abstract

A green approach: in a single-step coating process a mesoporous silica shell was tailored onto palladium-nanocubes. Along with a PEG-matrix this core–shell-nanocatalyst could be recovered after C–C-coupling reactions and reused without any significant decrease in product yield.

Palladium Nanoparticles Supported on Porous Silica Materials as Heterogeneous Catalysts of C−C Coupling and Cross‐Coupling Reactions

“…Rohleder and Vana synthesized mesoporous silica-coated Pd nanocubes, applied as a catalyst in the Heck coupling reaction. [125] The nanocubes were prepared in an aqueous solution, by using the precursor PdCl 2 , CTAB as surfactant, and ascorbic acid as a reducing agent. [126] The single-crystal structure of the Pd nanocubes of about 20 nm was confirmed by TEM images and selected area electron diffraction (SAED) patterns.…”

“…Rohleder and Vana synthesized mesoporous silica‐coated Pd nanocubes, applied as a catalyst in the Heck coupling reaction [125] . The nanocubes were prepared in an aqueous solution, by using the precursor PdCl 2 , CTAB as surfactant, and ascorbic acid as a reducing agent [126] .…”

Pd@l-asparagine–EDTA–chitosan: a highly effective and reusable bio-based and biodegradable catalyst for the Heck cross-coupling reaction under mild conditions

“…Recently, various heterogeneous Pd catalysts have been used in the HCR and other cross-coupling reactions, which have shown more advantages compared to homogeneous counterparts such as precluding the addition of different ligands, no Pd leaching in the final products, easy recycling and separation of overpriced Pd from the reaction medium, and reasonable application in industrial sectors. 21–37 Subsequently, from the greenness, cost-effectiveness, and safety point of view, it is essential to develop simple and effective procedures for the HCR by means of heterogeneous Pd catalysts. 31,38–46…”

“…Recently, various heterogeneous Pd catalysts have been used in the HCR and other cross-coupling reactions, which have shown more advantages compared to homogeneous counterparts such as precluding the addition of different ligands, no Pd leaching in the nal products, easy recycling and separation of overpriced Pd from the reaction medium, and reasonable application in industrial sectors. [21][22][23][24][25][26][27][28][29][30][31][32][33][34][35][36][37] Subsequently, from the greenness, cost-effectiveness, and safety point of view, it is essential to develop simple and effective procedures for the HCR by means of heterogeneous Pd catalysts. 31,[38][39][40][41][42][43][44][45][46] Heterogeneous metal catalysts are normally produced through the chelation of metal nanoparticles (NPs) on suitable solid supports and can simplify the separation and recovery of both catalysts and desired products from the reaction medium.…”