Palladium‐anchored multidentate SBA‐15/di‐urea nanoreactor: A highly active catalyst for Suzuki coupling reaction

Abstract

Modification of mesoporous silica was carried out by reaction of SBA‐15 with di‐urea‐based ligand. Next, with the help of this ligand, palladium ions were anchored within the multidentate SBA‐15/di‐urea pore channels with high dispersion. The SBA‐15/di‐urea/Pd catalyst was characterized using various techniques. Theoretical calculations indicated that each palladium ion was strongly interacted with one nitrogen and two oxygen atoms from the multidentate di‐urea ligand located in SBA‐15 channels and these interactions remained during the catalytic cycle. These results are in good agreement with those of hot filtration test: the palladium ions have very high stability against leaching from the SBA‐15/di‐urea support. The catalytic performance of SBA‐15/di‐urea/Pd nanostructure was examined for the Suzuki coupling reaction of phenylboronic acid and electronically diverse aryl halides under mild conditions with a minimal amount of Pd (0.26 mol%). Compared to previous reports, this protocol afforded some advantages such as short reaction times, high yields of products, catalyst stability without leaching, easy catalyst recovery and preservation of catalytic activity for at least six successive runs.

Thermoresponsive Polymer Gating System on Mesoporous Shells of Silica Particles Serving as Smart Nanocontainers

“…It has been reported that the size and shape of MSNs can be easily tailored by varying the temperature [7,8], reactants ratio [9], pH [10], surfactant chain length [11], as well as the addition of functional organosilanes [12]. Properly tailored MSNs found applications in numerous fields such as drug delivery systems [13,14], wastewater treatment [15,16], catalysis [17,18], fabrication of nanoreactors [19,20] and nanocontainers [21,22].…”

Epoxidation of cyclohexene with H2O2 over efficient water‐tolerant heterogeneous catalysts composed of mono‐substituted phosphotungstic acid on co‐functionalized SBA‐15

“…The N 2 sorption experiment was carried out to investigate the mesoscopic quality and textural properties of synthesized materials. As shown in Figure (a) and (b), all sorption isotherms exhibited typical IV‐type curves with clear H1‐type hysteresis loops, which was characteristic of a mesoporous structure with uniform pore size . This indicated that the ordered mesostructure was still maintained after introduction of organic moieties (viz.…”

Applications of SBA-15 supported Pd metal catalysts as nanoreactors in C–C coupling reactions

“…Finally, the SBA-15/di-urea/ Pd nanocatalyst was achieved by the reaction of Pd(OAc) 2 with SBA-15/di-urea (Scheme 75). 54 Typical SEM image of SBA-15/di-urea/Pd reveals rod-shaped morphology aggregated into bundles (Fig. 2a).…”

“…52 Moreover, in 2013, Molnár published a special book chapter concerning the applications of various ordered porous materials as solid supports in Pd-catalyzed cross-coupling reactions. 45 Taking the importance of this study and following our previous publications, 8,10,23,53,54 herein, we intend to review the applications of Pd-based mesoporous silica SBA-15 as catalyst in C-C couplings. The majority of this review is about the three most important C-C coupling reactions including the Suzuki-Miyaura (S-M), Mizoroki-Heck (M-H) and Sonogashira couplings with Pd anchored on SBA-15 catalysts.…”