A robust polyfunctional Pd(II)-based magnetic amphiphilic nanocatalyst for the Suzuki–Miyaura coupling reaction

Abstract

Herein, a robust Pd(II)-based polyfunctional magnetic amphiphilic artificial metalloenzyme was prepared by anchoring a Pd(2,2′-dipyridylamine)Cl2 bearing hydrophilic monomethyl ether poly(ethylene glycol) (mPEG) chains on the surface of amino-functionalized silica-coated magnetic nanoparticles. The 2,2′-dipyridylamine (dpa) has shown excellent complexation properties for Pd(II) and it could be easily anchored onto functionalized magnetic support by the bridging nitrogen atom. Moreover, the bridging nitrogen atom at the proximity of Pd(II) catalytic center could play an important role in dynamic suppramolecular interactions with substrates. The leaching, air and moisture resistant [Pd(dpa)Cl2] complex endow the dynamic and robust structure to the designed artificial enzyme. Moreover, the water dispersibility of designed artificial metalloenzyme raised from mPEG chains and the magnetic nanoparticles core which could function as protein mimics endow it other necessary characters of artificial enzymes. The prepared artificial metalloenzyme displayed remarkable activity in Suzuki–Miyaura cross-coupling reaction employing low-palladium loading under mild conditions, with the exceptionally high turnover frequency, clean reaction profile, easy work-up procedure, good to excellent products yields and short reaction times. The designed air- and moisture-stable artificial metalloenzyme could recycle more than fifteen times with easy separation procedure in aqueous solution under aerobic conditions without any noticeable loss in activity.

Phenazine‐based supramolecular photosensitizing assemblies: A “smart” selectivity control on catalytic activity of Pd(II) nanoparticles

“…The powder X‐ray diffraction (XRD) studies of the precipitates obtained after the evaporation of a solution of PPA and Pd 2+ ions in H 2 O/THF (7/3, v/v) show the peaks around 40°, 46°, 67°, and 81° corresponding to (111), (200), (220), and (311) planes of crystal face‐centered cubic ( fcc ) lattice of Pd, respectively (Supporting Information, Figure S9). [ 10b,28,29 ] The dynamic light scattering (DLS) studies confirm the average size of nanomaterial in the range of 65–78 nm (Figure S10). Furthermore, energy‐dispersive spectroscopy (EDS) mapping of PPA@Pd NPs also shows the presence of Pd (Figure S11).…”

“…[29] In the X-ray photoelectron spectroscopy (XPS) spectrum of PPA@Pd NPs, two distinct and intense peaks are observed at 338.18 and 343.43 eV, which confirm the presence of Pd 2+ ions. 29 In addition to these peaks, the XPS spectrum for PPA@Pd NPs also shows satellite peaks for Pd 2+ ions at 339.73 and 344.83 eV (Figure 3). [30] After completing the characterization of PPA@Pd NPs, we examined the photosensitization potential of PPA assemblies.…”

“…Furthermore, energy‐dispersive spectroscopy (EDS) mapping of PPA@Pd NPs also shows the presence of Pd (Figure S11). [ 29 ] In the X‐ray photoelectron spectroscopy (XPS) spectrum of PPA@Pd NPs, two distinct and intense peaks are observed at 338.18 and 343.43 eV, which confirm the presence of Pd 2+ ions. 29 In addition to these peaks, the XPS spectrum for PPA@Pd NPs also shows satellite peaks for Pd 2+ ions at 339.73 and 344.83 eV (Figure 3).…”

Magnetic ethylene-based periodic mesoporous organosilica supported palladium: An efficient and recoverable nanocatalyst for Suzuki reaction

“…Therefore, in recent years many researchers have studied and evaluated the optimization of this reaction using efficient catalytic systems ( Dong et al, 2021 ; Favalli et al, 2021 ; Kempasiddaiah et al, 2021 ; Kim et al, 2021 ). Some of recently reported catalysts in this matter are Fe 3 O 4 @SiO 2 @NHC@Pd-MNPs ( Akkoç et al, 2021 ), Fe 3 O 4 /Pd ( Veisi et al, 2021 ), Fe 3 O 4 @SiO 2 /glucosamine-Pd ( Eslahi et al, 2021 ), SiO 2 -NH 2 @Pd (dpa)Cl 2 ( Aghahosseini et al, 2021 ), Fe 3 O 4 /SiO 2 -NH 2 @CS/Pd ( Veisi et al, 2020 ), Fe 3 O 4 @MCM-41-SB/Pd ( Shaker and Elhamifar, 2020a ), PEt@ IL/Pd ( Kargar and Elhamifar, 2020 ), GO-N 2 S 2 /Pd ( Zarnegaryan and Elhamifar, 2020 ) and GO–SB/Pd ( Zarnegaryan et al, 2019 ). In view of the above, in the present work, for the first time, a novel Fe 3 O 4 @Et-PMO supported Pd-Schiff base complex is prepared, characterized and its catalytic application is studied in the Suzuki reaction.…”

Palladium-catalyzed Suzuki–Miyaura cross-coupling with α-aminophosphonates based on 1,3,4-oxadiazole as ligands

“…Interestingly, several nitrogenated ligands have been also employed for the Suzuki-Miyaura cross-coupling. We can quote for example the use of Schiff bases [44][45][46][47][48][49][50], amines [51,52], azo compounds [53], pyridines [54][55][56][57][58], pyrimidines [59,60], triazoles [61] or benzimidazoles [62]. However, despite their relevance, these catalytic systems suffer from one or more drawbacks such as the use of expensive or difficultly accessible ligands, as well as high catalyst loading, hazardous solvents and harsh reaction conditions.…”