135-69-3Relevant articles and documents
Invisible Chelating Effect Exhibited between Carbodicarbene and Phosphine through π-π Interaction and Implication in the Cross-Coupling Reaction
Shih, Wei-Chih,Chiang, Yun-Ting,Wang, Qing,Wu, Ming-Chun,Yap, Glenn P. A.,Zhao, Lili,Ong, Tiow-Gan
, p. 4287 - 4297 (2017)
Palladium complexes supported with the mixed ligands carbodicarbene (CDC) and different phosphine ligands (PPh3, PTol3, and PCy3) were prepared, and their molecular structures were characterized. Examination of the structures of 2-PPh3 and 2-PTol3 with cis configuration discloses the existence of an unexpected π-π interaction between one phenyl group of the phosphine and the benzimidazole ring of a CDC. The palladium complex 2-PPh3 is an active Suzuki-Miyaura catalyst with a wide scope of substrates containing various functional groups and steric demands. In contrast to electron-withdrawing aryl bromide, the yield of product for electron-rich substrates was improved by adding a catalytic amount of DMSO under aerobic conditions. The solution NMR and structural analysis has revealed that the intramolecular π-π interaction between CDC and phosphine ligands has a positive influence on the activity of the reaction, which is further supported by quantum chemical calculations.
Suzuki-Miyaura cross-coupling catalyzed by protein-stabilized palladium nanoparticles under aerobic conditions in water: Application to a one-pot chemoenzymatic enantioselective synthesis of chiral biaryl alcohols
Prastaro,Ceci,Chiancone,Boffi,Cirilli,Colone,Fabrizi,Stringaro,Cacchi
, p. 1929 - 1932 (2009)
The preparation of palladium nanoparticles stabilized primarily within the protein cavity of a highly thermostable Dps protein (DNA binding protein from starved cells) and the use of this precatalyst system in Suzuki-Miyaura cross-coupling reactions under
Alcoholic solvent-assisted ligand-free room temperature Suzuki-Miyaura cross-coupling reaction
Sarmah, Gayatri,Mondal, Manoj,Bora, Utpal
, p. 495 - 498 (2015)
We have observed the enhancing effect of alcoholic solvents in palladium-catalysed ligand-free Suzuki-Miyaura reactions. No extra additives or ligands are required for the Suzuki-Miyaura reaction of aryl bromides with arylboronic acids when we carried out the reaction in alcoholic or aqueous alcoholic solvents. Moreover, ethanol or aqueous ethanol is found to be a very good solvent for the Suzuki-Miyaura reaction involving electronically diverse aryl bromides and arylboronic acids under mild and ligand-free conditions with low catalyst loading. It is observed from Hg(0) poisoning tests that the in situ generated palladium(0) species is the actual catalytic species for the reaction.
Palladium stabilized by 3,4-dihydroxypyridine-functionalized magnetic Fe3O4 nanoparticles as a reusable and efficient heterogeneous catalyst for Suzuki reactions
Pirhayati, Mozhgan,Veisi, Hojat,Kakanejadifard, Ali
, p. 27252 - 27259 (2016)
A Pd supported on 3,4-dihydroxypyridine (Py)-functionalized Fe3O4 (Fe3O4/Py/Pd) hybrid material has been synthesized for the first time. Inductively coupled plasma (ICP), energy dispersive X-ray spectroscopy (EDX), transmission electron microscopy (TEM), scanning electron microscopy (SEM), and field emission scanning electron microscopy (FESEM) and Fourier transform infrared (FTIR) studies have been used to characterize the catalyst. The catalyst exhibited very high activity for Suzuki coupling reaction of several aryl halides with phenylboronic acids in aqueous phase at room temperature. The most interesting result of this work is the possibility to perform Suzuki reactions of aryl chlorides in the presence of the prepared catalyst. The yields of the products were in the range from 70% to 98%. In this process, the novel catalyst could be recovered in a facile manner from the reaction mixture by applying an external magnet device, and reused more than eight times without any significant loss in activity.
Palladium nanoparticles embedded in metal-organic framework derived porous carbon: Synthesis and application for efficient Suzuki-Miyaura coupling reactions
Dong, Wenhuan,Zhang, Li,Wang, Chenhuan,Feng, Cheng,Shang, Ningzhao,Gao, Shutao,Wang, Chun
, p. 37118 - 37123 (2016)
A nanoporous carbon (NPC) material was prepared by one-step direct carbonization of a metal-organic framework, MOF-5, without additional carbon precursors. Pd nanoparticles were immobilized on the MOF-5-derived NPC by an impregnation method coupled with subsequent reduction with NaBH4. The prepared catalyst was in-depth characterized by X-ray photoelectron spectroscopy, transmission electron microscopy, scanning electron microscopy, and N2 adsorption. The catalyst was used to catalyze the Suzuki-Miyaura coupling reactions and exhibited high catalytic efficiency with yields ranging from 90% to 99% under mild conditions. The results demonstrated the great application potential of MOF precursor-based metal nanoparticle composites in catalysis.
Importance of monodentate mono-ligand designs in developing N-stabilized Pd catalysts for efficient ambient temperature C[sbnd]C coupling: Donor strengths and steric features
Eseola, Abiodun Omokehinde,G?rls, Helmar,Plass, Winfried
, (2019)
Unfriendly temperature profiles and costs of carbon coupling catalysis, which pose challenge to both synthetic organic chemists as well as industrial applicability, motivated our design of new monodentate N-donors as support ligands for the purpose of constructing ambient temperature precatalysts that are molecularly close to the hypothetical active forms. Therefore, a series of sterically varied monodentate N-donor imidazoles (1–7) and oxazoles (8–9) have been synthesized and their N-donor strengths, which were estimated as pKas, are systematically varied from 0.9 to 8.5 by substituent variations. Eleven target mono-ligand complexes (1-PdCl2MeCN – 9-PdCl2MeCN, 6-PdCl2PhCN and 7-PdCl2PhCN) and six trans-bis-ligand complexes (12-PdCl2, 22-PdCl2, 32-PdCl2, 62-PdCl2, 12-Pd(OAc)2 and 22-Pd(OAc)2) were isolated and catalytically studied along with PdI2(PPh3)2. Results of coupling reactions, which were conducted both via in situ ‘Pd(II) salt + ligand’ approach and by use of the precatalysts, show that the mono-ligand precatalyst designs (1-PdCl2MeCN – 9-PdCl2MeCN, 6-PdCl2PhCN and 7-PdCl2PhCN) represent a true catalyst improvement initiative among the phosphine-free catalyst community; i.e. yields approaching 100% (TOF ≈ 2000) at 0.2 mol % catalyst loading, 45 °C and within 15 min. On the other hand, the complexes with trans-bis-ligand coordination were inactive at ambient temperatures. Therefore, it was concluded that coordinative saturation, which results from implementing two or more ligand equivalents or use of polydentate ligands on palladium, should be strongly discouraged. Such saturation necessitates the undesirable and avoidable high temperature necessities, long reflux durations and needlessly high catalyst loadings. Correlation between catalyst activity and donor strengths or steric properties were analysed leading to important conclusions. The catalyst design also supported coupling of activated aryl chlorides from 60 °C while Heck coupling activities were observed only at the early minutes of reactions.
Magnetic chitosan-functionalized cobalt-NHC: Synthesis, characterization and catalytic activity toward Suzuki and Sonogashira cross-coupling reactions of aryl chlorides
Hajipour, Abdol R.,Malek, Shaghayegh Sadeghi
, (2021/04/23)
Aryl chlorides are one of the most stable and available electrophiles, however, their coupling with nucleophiles remains a challenge in organic synthesis. Herein, we prepared a Cobalt-NHC (N-Heterocyclic carbene) complex anchored on magnetic chitosan nanoparticles and assayed its catalytic activity for the reactions of substituted phenylboronic acid and also phenlacetylene with derivatives of aryl chlorides. These reactions are of great importance since they are employed for the synthesis of unsymmetrical diarylethynes and biphenyls, which belong to a prime class of building blocks. The synthesized nanocatalyst was found to be highly efficient in Suzuki and Sonogashira coupling in terms of their activity and recyclability in polyethylene glycol (PEG) as a green reaction media under conditions of temperatures (70 and 100 °C) and Co loading (3 and 6 mol%). To the best of our knowledge, this is the first attempt of using cobalt-NHC complex for catalyzing the abovementioned reactions. Moreover, replacing the earth-abundant Cobalt-based catalyst as an alternative to high cost palladium make this approach promising from sustainable chemistry view.
Self-Assembled Multilayer Iron(0) Nanoparticle Catalyst for Ligand-Free Carbon-Carbon/Carbon-Nitrogen Bond-Forming Reactions
Akiyama, Toshiki,Arisawa, Mitsuhiro,Haneoka, Hitoshi,Harada, Kazuo,Hasegawa, Jun-Ya,Honma, Tetsuo,Mashima, Kazushi,Sato, Yoshihiro,Shimoda, Shuhei,Shio, Yasunori,Suzuki, Takeyuki,Tamenori, Yusuke,Tsurugi, Hayato,Tsuruta, Kazuki,Wada, Yuki,Yamada, Makito
supporting information, p. 7244 - 7249 (2020/10/12)
Self-assembled multilayer iron(0) nanoparticles (NPs, 6-10 nm), namely, sulfur-modified Au-supported Fe(0) [SAFe(0)], were developed for ligand-free one-pot carbon-carbon/carbon-nitrogen bond-forming reactions. SAFe(0) was successfully prepared using a well-established metal-nanoparticle catalyst preparative protocol by simultaneous in situ metal NP and nanospace organization (PSSO) with 1,4-bis(trimethylsilyl)-1,4-dihydropyrazine (Si-DHP) as a strong reducing agent. SAFe(0) was easy to handle in air and could be recycled with a low iron-leaching rate in reaction cycles.
