2367-22-8Relevant articles and documents
Mono- and dinuclear palladium(II) complexes containing both N-heterocyclic carbenes and tetrazole ligands as catalysts for Hiyama coupling
Yang, Jin
, p. 9739 - 9745 (2016)
Treatment of the dimeric compounds [Pd(μ-Cl)(Cl)(NHC)]2 with tetrazole ligands afforded a series of tetrazole ligand stabilized NHC-Pd complexes, including [PdCl2(IPr)(1H-tetrazole)] (1), [PdCl2(SIPr)(1H-tetrazole)] (2), [PdCl2(IPr)(1-phenyl-1H-tetrazole)] (3), [PdCl2(SIPr)(1-phenyl-1H-tetrazole)] (4), [Pd2(μ-Cl)(μ-5-phenyl-2H-tetrazole)Cl2(IPr)2] (5) and [Pd2(μ-Cl)(μ-5-pheny-2H-ltetrazole)Cl2(SIPr)2] (6) [IPr = N,N′-bis-(2,6-di(isopropyl)phenyl)imidazol-2-ylidene; SIPr = N,N′-bis-(2,6-di(isopropyl)phenyl)imidazolidin-2-ylidene]. Notably, compounds 1-4 are mononuclear NHC-Pd complexes, while compounds 5 and 6 show unprecedented μ-Cl and μ-5-phenyl-2H-tetrazole bridged dinuclear structures. The catalytic properties of the obtained NHC-Pd complexes in Hiyama coupling were initially investigated.
Biogenous iron oxide-immobilized palladium catalyst for the solvent-free Suzuki-Miyaura coupling reaction
Mandai, Kyoko,Korenaga, Toshinobu,Ema, Tadashi,Sakai, Takashi,Furutani, Mitsuaki,Hashimoto, Hideki,Takada, Jun
, p. 329 - 332 (2012)
Iron oxide produced by iron-oxidizing bacteria, Leptothrix ochracea, (biogenous iron oxide: BIO) was used as a support for immobilized palladium catalysts with organic cross-linkers. Palladium immobilized on BIO bearing imidazolium chloride delivered the desired biaryl products in sufficient yields in the Suzuki-Miyaura coupling reactions under solvent-free conditions and could be reused several times without significant loss of catalytic activity. It is shown that BIO can be exploited as a useful support for immobilization of palladium and the BIO-immobilized palladium catalyst effectively promotes the solvent-free Suzuki-Miyaura coupling reactions.
Air-stable and catalytically active phosphinous acid transition-metal complexes
Kurscheid, Boris,Belkoura, Lhoussaine,Hoge, Berthold
, p. 1329 - 1334 (2012)
Secondary phosphane oxides R2P(O)H are most frequently used as preligands for phosphinous acid R2POH (R = alkyl, aryl) transition-metal complexes, which are very efficient catalysts for cross-coupling reactions. To investigate the influence of electron-deficient substituents on the catalytic activity, the coordination properties of bis(trifluoromethyl)-, bis(pentafluoroethyl)-, and bis[2,4-bis(trifluoromethyl) phenyl]phosphinous acid toward catalytically relevant metals, such as palladium and platinum, are studied. The novel phosphinous acid palladium complexes reveal a high catalytic activity in Heck and Suzuki cross-coupling reactions. Because of the strong dependence of these processes on the reaction conditions, a systematic solvent and base screening with 1-bromo-3-fluorobenzene and phenyl boronic acid as model reactants is performed. The most efficient solvent/base system consists of 2-propanol and potassium phosphate, providing a full conversion and a TON of around 10 000 after 20 h at room temperature with a catalyst loading of 0.01 mol % palladium. A catalyst loading of only 0.004 mol % palladium still leads to a nearly full conversion after 20 h at room temperature. During the catalytic reaction, the formation of the corresponding phosphinic acid R2P(O)OH is observed. Further investigations lead to the conclusion that palladium nanoparticles represent the catalytically active species. We also succeeded in the generation of palladium nanoparticles, which exhibit an extremely high catalytic activity in Suzuki cross-coupling reaction with TONs over 60 000 and TOFs larger than 40 000.
Cerium photosensitizers: Structure-function relationships and applications in photocatalytic aryl coupling reactions
Yin, Haolin,Carroll, Patrick J.,Manor, Brian C.,Anna, Jessica M.,Schelter, Eric J.
, p. 5984 - 5993 (2016)
Two complete mixed-ligand series of luminescent CeIII complexes with the general formulas [(Me3Si)2NC(NiPr)2]xCeIII[N(SiMe3)2]3-x (x = 0, 1-N; x = 1, 2-N, x = 2, 3-N; x = 3, 4) and [(Me3Si)2NC(NiPr)2]xCeIII(OAr)3-x (x = 0, 1-OAr; x = 1, 2-OAr, x = 2, 3-OAr; x = 3, 4) were developed, featuring photoluminescence quantum yields up to 0.81(2) and lifetimes to 117(1) ns. Although the 4f ? 5d absorptive transitions for these complexes were all found at ca. 420 nm, their emission bands exhibited large Stokes shifts with maxima occurring at 553 nm for 1-N, 518 nm for 2-N, 508 nm for 3-N, and 459 nm for 4, featuring yellow, lime-green, green, and blue light, respectively. Combined time-dependent density functional theory (TD-DFT) calculations and spectroscopic studies suggested that the long-lived 2D excited states of these complexes corresponded to singly occupied 5d 2 orbitals. The observed difference in the Stokes shifts was attributed to the relaxation of excited states through vibrational processes facilitated by the ligands. The photochemistry of the sterically congested complex 4 was demonstrated by C-C bond forming reaction between 4-fluoroiodobenzene and benzene through an outer sphere electron transfer pathway, which expands the capabilities of cerium photosensitizers beyond our previous results that demonstrated inner sphere halogen atom abstraction reactivity by 1-N.
Organocatalytic synthesis of (Het)biaryl scaffoldsviaphotoinduced intra/intermolecular C(sp2)-H arylation by 2-pyridone derivatives
Das, Tapas Kumar,Kundu, Mrinalkanti,Mondal, Biswajit,Ghosh, Prasanjit,Das, Sajal
, p. 208 - 218 (2021/12/29)
A uniqueN,O-bidentate ligand 6-oxo-1,6-dihydro-pyridone-2-carboxylic acid dimethylamide (L1) catalyzed direct C(sp2)-H (intra/intermolecular) arylation of unactivated arenes has been developed to expedite access to (Het)biaryl scaffolds under UV-irradiation at room temperature. The protocol tolerated diverse functional groups and substitution patterns, affording the target products in moderate to excellent yields. Mechanistic investigations were also carried out to better understand the reaction pathway. Furthermore, the synthetic applicability of this unified approach has been showcasedviathe construction of biologically relevant 4-quinolone, tricyclic lactam and sultam derivatives.
Anchored PdCl2 on fish scale: an efficient and recyclable catalyst for Suzuki coupling reaction in aqueous media
Yang, Quanlu,Yang, Fawang,Zhang, Ying,Hou, Juanjuan,Li, Jiankun,Cheng, Jinkui,Wu, Shang,Zhan, Huiying,Zhang, Xinghui,Shi, Haixiong
supporting information, (2020/12/25)
PdCl2 anchored on fish scale (FS) complex were intended to a heterogeneous catalyst for ligand-free Suzuki coupling reaction in aqueous media. The catalyst FS-PdCl2 was characterized by FT-IR, powder XRD, XPS and SEM. FS-PdCl2 complex has been successfully implemented for Suzuki coupling reactions of various halogenated aromatics with arylboronic acid to provide the corresponding biaryl compounds under environmentally friendly conditions (40 °C, water solvent). Moreover, the efficient catalyst shows excellent stability and recyclability, and its catalytic activity without any decrease after 8 times consecutive reused.
Highly Active Heterogeneous PdCl2/MOF Catalyst for Suzuki–Miyaura Cross-Coupling Reactions of Aryl Chloride
Gong, Xue-Fang,Zhang, Ling-Yan,Zhang, Hui-Xin,Cui, Yu-Meng,Jin, Fen-Chun,Liu, Yu,Zhai, Yu-Feng,Li, Jin-Heng,Liu, Gui-Yan,Zeng, Yong-Fei
, p. 1336 - 1341 (2020/07/06)
The exploration of highly efficient Pd/MOF heterogeneous catalyst system for the Suzuki–Miyaura cross-coupling (SMC) reactions of aryl chlorides is still challenging. Herein, a PdCl2/UiO-67-bpydc was successfully synthesized by immobilizing a low amount of PdCl2 onto the zirconium-based MOF (UiO-67-bpydc). PdCl2/UiO-67-bpydc showed excellent catalytic performance and good recycle ability for the SMC reaction of aryl chlorides under an ambient condition. Furthermore, PdCl2/UiO-67-bpydc retains the high catalytic activity even after five cycles, and exhibited excellent substrate size selectivity.
