Pd(diimine)Cl2 embedded heterometallic compounds with porous structures as efficient heterogeneous catalysts

Abstract

Four porous heterometallic coordination polymers were synthesized via a metalloligand strategy. All of them contain the [Pd(diimine)Cl(2)] moiety, which has good catalytic activity, and present remarkable versatility for catalysing Suzuki-Miyaura and Heck reactions.

Efficient Suzuki–Miyaura C-C Cross-Couplings Induced by Novel Heterodinuclear Pd-bpydc-Ln Scaffolds

“…An increase in the product yield with temperature is the general trend for the three catalysts. This result is in accordance with the fact that palladium-catalyzed cross-coupling in organic solvents is conveniently performed at higher temperature [83]. Under all tested conditions, Pd-bpydc-Nd ( 3 ) is clearly the best catalyst (Table 1, entries 9–12) affording highest yields (Figure 1) and selectivities.…”

“…As will be seen below, the lanthanides play a significant role in tailoring in several ways the catalytic properties of the palladium complexes. Working either at 30 °C or 60 °C and at low catalyst loadings the activity of Pd-bpydc-Nd ( 3 ) (yield: 95%; Table 1, entry 9 and 11) surpasses that of the previously reported Pd(diimine)Cl 2 embedded heterobimetallic (Pd-Ln) heterogeneous catalysts [83] which have a related structure but contain another lanthanide (i.e., Ln = Sm). A sharp variation in product yield and catalyst activity with temperature was found for Pd-bpydc-Ce ( 2 ); this catalyst proved to be highly active at 60 °C, even for a low catalyst loading (Table 1, entry 7 and 8) but displayed lower yields at 30 °C (Table 1, entry 5 and 6) under the employed reaction conditions (8 h reaction time, 0.2 mol % or 0.5 mol % catalyst loading).…”

“…In such multifunctional configurations, the lanthanide nodes are interconnected by appropriate organic linkers to form rigid porous networks which attach PdCl 2 , prone to catalyze C-C bond formation. Thus, Jin and coworkers [83] ingeniously combined Pd nitrophilic metal cations, which coordinate diimine groups from the 2,2′-bipyridine-5,5′-dicarboxylate (bpydc) linker, with the Ln oxophilic rare earth metals (Ln = Sm, Eu, Gd or Tb) to build-up MOFs displaying a good heterogeneous catalytic activity for C-C cross-coupling reactions. With Ln(bpydc)PdCl 2 embedded MOFs they performed the Suzuki–Miyaura reaction of selected aryl halides with arylboronic acid in toluene at 95 °C reporting appreciable yields in biaryls (82–97% yields, 4 h).…”

Pd–Ni Alloy Nanoparticles as Effective Catalysts for Miyaura–Heck Coupling Reactions

“…32 However, in many cases, the Heck reaction is generally carried out in the presence of phosphine ligands under an inert atmosphere in order to minimize the poisonous effect of oxygen in the air. In the current work, we hope to develop the catalyst which can not only reduce the usage of palladium but also can be exposed to the air.…”

Breathing 3D Frameworks with T-Shaped Connecting Ligand Exhibiting Solvent Induction, Metal Ions Effect and Luminescent Properties

“…The multidentate ligand 2,2 -bipyridine-5,5 -dicarboxylic acid (H 2 bpdc) is a good candidate because it contains two types of coordination groups-carboxylate groups and chelating position N-donors-which can act in linear bridging mode and/or T-shaped connecting mode [20][21][22][23][24][25][26][27][28][29][30][31][32][33][34][35][36][37]. To date, there are 20 different coordination modes for H 2 bpdc ligand observed in the structures retrieved from the Cambridge Structural Database (CSD version 5.38, February 2017) [38] (Figure 1, Scheme S1).…”