An efficient Pd–NHC catalyst system in situ generated from Na₂PdCl₄ and PEG-functionalized imidazolium salts for Mizoroki–Heck reactions in water

• Nan Sun,
• Meng Chen,
• Liqun Jin,
• Wei Zhao,
• Baoxiang Hu,
• Zhenlu Shen and
• Xinquan Hu

Beilstein J. Org. Chem. 2017, 13, 1735–1744, doi:10.3762/bjoc.13.168

• materials via a simple method. Their corresponding water soluble Pd–NHC catalysts, in situ generated from the imidazolium salts L1–L3 and Na2PdCl4 in water, showed impressive catalytic activity for aqueous Mizoroki–Heck reactions. The kinetic study revealed that the Pd catalyst derived from the imidazolium

• 10,000. Keywords: aqueous homogeneous catalysis; Mizoroki–Heck reaction; Na2PdCl4; PEG-functionalized imidazolium salts; Introduction Nowadays, both increasing environmental concerns and drastic commercial competition are the driving forces to develop more sustainable and economic processes for

• ) and styrene (2a) as the substrates, water as solvent and Na2PdCl4/L1 as the catalyst. The mixture of Na2PdCl4, L1 and base in water were preheated at 60 °C for 30 min before the addition of substrates [41]. The effect of base was first explored. As the selected experimental results illustrated in

Encaging palladium(0) in layered double hydroxide: A sustainable catalyst for solvent-free and ligand-free Heck reaction in a ball mill

• Wei Shi,
• Jingbo Yu,
• Zhijiang Jiang,
• Qiaoling Shao and
• Weike Su

Beilstein J. Org. Chem. 2017, 13, 1661–1668, doi:10.3762/bjoc.13.160

• catalytic activity in coupling reactions than that on acidic-supported materials. In the present work, co-precipitation was used for fabricating MgAl-LDHs with nitrate anions, followed by introducing disodium tetrachloropalladate (Na2PdCl4) into the LDH interlayer by the ion exchange method. The prepared

New palladium–oxazoline complexes: Synthesis and evaluation of the optical properties and the catalytic power during the oxidation of textile dyes

• Rym Hassani,
• Mahjoub Jabli,
• Yakdhane Kacem,
• Jérôme Marrot,
• Damien Prim and
• Béchir Ben Hassine

Beilstein J. Org. Chem. 2015, 11, 1175–1186, doi:10.3762/bjoc.11.132

• of the heterocycles. The addition of one equivalent of 7 to a methanolic solution of Na2PdCl4 gave the palladium complex 8 in 75% yield. The coordination sphere has two chlorine atoms bonding in a cis configuration to the Pd center and the oxazoline ligand chelating to the Pd center via the two

• methanolic solution of Na2PdCl4 at room temperature gave the palladium complexes 9 and 12 in 85% and 68% yields, respectively (Scheme 3). The two complexes are stable when exposed to air and water. The single crystal X-ray model of complex 9 is depicted in Figure 3 (see Supporting Information File 2 for the

• tetrachloropalladate(II) Na2PdCl4 (0.34 mmol, 1 equiv) in absolute MeOH (3 mL) was added to (0.75 mmol, 2.2 equiv) of the ligand. A yellow precipitate was formed immediately. The mixture was stirred for 24 h at room temperature. After removal of the solvent under reduced pressure, the yellow solid was washed with

Scaling up of continuous-flow, microwave-assisted, organic reactions by varying the size of Pd-functionalized catalytic monoliths

• Ping He,
• Stephen J. Haswell,
• Paul D. I. Fletcher,
• Stephen M. Kelly and
• Andrew Mansfield

Beilstein J. Org. Chem. 2011, 7, 1150–1157, doi:10.3762/bjoc.7.133

• with microwave heating. The silica monoliths were impregnated with a range of Pd precursors, namely Na2PdCl4, Pd(OAc)2, Pd(dba)2 and Pd(NO3)2, by a standard method described previously for the preparation of Pd-monoliths. The Pd-monolith-3.2 catalysts were evaluated using the previously optimized

• , showing a significant effect of the palladium precursor on the catalyst activity. The Pd-monolith catalyst that was synthesized from a Na2PdCl4 precursor showed the best activity and was therefore used as the Pd precursor for the preparation of a Pd-monolith catalyst to be employed in further

• -monolith at 0.1 mL/min for 20 min. For the Na2PdCl4 based monolithic catalyst, the amount of palladium present in the washing liquid was found to be as little as 74 ppb (Pd-monolith-3.2), corresponding to a loss of only 0.000011% of the initial amount of palladium added to the monoliths. The amount of

Polyionic polymers – heterogeneous media for metal nanoparticles as catalyst in Suzuki–Miyaura and Heck–Mizoroki reactions under flow conditions

• Klaas Mennecke and
• Andreas Kirschning

Beilstein J. Org. Chem. 2009, 5, No. 21, doi:10.3762/bjoc.5.21

• that the resin can only swell inside the glass while the glass monolith provides a stable rod-like shape inside the microreactor. The Merrifield-type resin was aminated to yield polyionic support 1. This polymer serves as an anchor to leave the metal species (sodium tetrachloropalladate; Na2PdCl4) in