144374-53-8Relevant articles and documents
Syntheses and catalytic activities of Pd(II) dicarbene and hetero-dicarbene complexes
Huynh, Han Vinh,Jothibasu, Ramasamy
, p. 3369 - 3375 (2011)
A series of palladium(II) complexes (1-6) bearing cis-chelating homo-dicarbene ligands with varying alkyl bridges (C1-C3) and N-heterocyclic backbones (imidazole and benzimidazole) have been synthesized by reaction of Pd(OAc)2 with the respective diazolium bromides (A·2HBr - F·2HBr) in DMSO. A comparative catalytic study employing aryl chlorides in the Mizoroki-Heck reaction revealed the superiority of methylene- and propylene-bridged dibenzimidazolin-2-ylidenes over their imidazole-derived analogues. Based on these results, two new propylene-bridged hetero-dicarbene complexes (7 and 8) were designed containing a mixed benzimidazole/imidazole- derived NHC-donor set. Notably, both complexes outperformed their homo-dicarbene analogues, which may be due to the electronic asymmetry induced by hetero-dicarbene ligands. The molecular structures of complex 6 and 8 are also presented.
Highly effective cellulose supported 2-aminopyridine palladium complex (Pd(II)-AMP-Cell?Al2O3) for Suzuki-Miyaura and Mizoroki–Heck cross-coupling
Mhaldar, Pradeep,Pore, Dattaprasad,Rashinkar, Gajanan,Vibhute, Sandip
, (2020/04/15)
In the present work, a novel, highly efficient, retrievable organo–inorganic hybrid heterogeneous catalyst (Pd(II)-AMP-Cell?Al2O3) has been prepared by covalent grafting of 2-aminopyridine on chloropropyl modified cellulose-alumina composite followed by complexation with palladium acetate. The catalyst was characterized by techniques such as scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), inductive coupled plasma-atomic emission spectroscopy (ICP-AES) and thermo gravimetric analysis (TGA). The catalyst has been successfully employed in Suzuki-Miyaura as well as Mizoroki–Heck cross-coupling reactions. The reactions proceed smoothly resulting in the high yields of cross-coupling products (81 to 95%) within short reaction times. The catalyst can be efficiently recovered by simple filtration and reused for multiple cycles without considerable loss in the catalytic activity. The key-features of the present protocol include mild reaction conditions, simple work-up procedure, high stability of the catalyst, high turnover number (TON) and frequency (TOF), ease recovery and reusability of the catalyst.
Mono- and dinuclear palladium(II) complexes incorporating 1,2,3-triazole-derived mesoionic carbenes: syntheses, solid-state structures and catalytic applications
Zhang, Xin,Yan, Xuechao,Zhang, Bo,Wang, Ran,Guo, Shuai,Peng, Shiyong
, p. 39 - 48 (2018/08/06)
Two 1,2,3-triazole-derived monocationic salts 3 and 4 bearing N-aryl wingtips were prepared using copper-catalyzed “click” reactions followed by alkylations with iodomethane. Employing a silver–carbene transfer method, two dinuclear palladium(II) complexes of triazolin-5-ylidenes (5/6) were obtained, the former of which has been reported previously. Bridge-cleavage reaction of 5 as a representative with PPh3 yielded cis-configured mesoionic carbene/phosphine hybrid complex cis-7 and homoleptic bis(phosphine) complex 8, suggesting the presence of a ligand exchange process. In contrast, bridge breakages of 5/6 with pyridine cleanly afforded PEPPSI-type complexes 9 and 10 in near quantitative yields. Finally, all complexes were exploited to catalyze Mizoroki–Heck coupling reactions with aryl bromides as the substrates, and PEPPSI-type complex 9 was found to be the best performer generally giving good to excellent yields.
Self-assembled Pd nanoparticle-containing ionic liquid: Efficient and reusable catalyst for the Heck reaction in water
Zong, Yingxiao,Wang, Junke,An, Pengli,Yue, Guoren,Pan, Yi,Wang, Xicun
, p. 2389 - 2396 (2017/09/30)
A self-assembled Pd nanoparticle-containing ionic liquid as metal–organic polymer was successfully prepared. The structure of the catalyst was characterized using Fourier transform infrared and 1H NMR spectroscopies, scanning electron microscopy and elemental analysis. The catalyst was effectively employed in the palladium-catalyzed Heck reaction in water as a green solvent. Moreover, due to its stability the catalyst can be recovered simply and effectively and reused nine times without much loss of activity.
Pd and Ni complexes of a novel vinylidene β-diketimine ligand: Their application as catalysts in Heck coupling and alkyne trimerization
Beesam, Raghavendra,Nareddula, Dastagiri Reddy
, (2017/09/01)
A β-diketimine ligand with vinylidene substitution at γ-carbon, CH2C(CH3CNAr)2 (Ar?=?2,6-diisopropylphenyl) (L2), was synthesized by treating β-diketimine H2C(CH3CNAr)2 with n-BuLi followed by paraformaldehyde. L2 formed the homobimetallic ether-bridged β-diketiminate complex [O{(CH2-β-diketiminate)Pd(OAc)}2] (1) with (PdOAc)2. It also gave complexes [L2PdCl2] (2) and [L2NiBr2] (3) when treated with PdCl2(CH3CN)2 and NiBr2(dimethoxyethane), respectively. All the compounds were characterized using 1H/13C NMR spectroscopy and single-crystal X-ray diffraction studies. The catalytic activity of Pd and Ni complexes 1, 2 and 3 was explored in Heck coupling and alkyne trimerization reactions and it was found that they are very good catalysts. The results are reported in detail.
RETRACTED ARTICLE: A Recycling-Free Nanocatalyst System: The Stabilization of in Situ-Reduced Noble Metal Nanoparticles on Silicone Nanofilaments via a Mussel-Inspired Approach
Fei, Xiang,Kong, Wangqing,Chen, Xin,Jiang, Xuejiao,Shao, Zhengzhong,Lee, Jim Yang
, p. 2412 - 2418 (2017/06/01)
The recovery and reuse of costly nanocatalysts is an essential operation in modern nanocatalysis, and improvements in catalyst reusability can contribute significantly to the economic viability and sustainable development of nanocatalysis. Herein, starting with the application of a silicone nanofilament (SNF) coating on a target substrate, a mussel-inspired approach in the form of polydopamine (PDA) deposition on the SNF surface was used to form in situ-reduced Pd nanoparticles (Pd NPs) and to stabilize them on the SNFs. This PDA-mediated approach enabled a high integrity nanocatalyst system to be built on a free-standing SNF support while retaining the porosity in the original SNF architecture. The SNFs-Pd nanocomposites prepared as such were applied to the inside walls of laboratory chemical reactors and used as recycling-free nanocatalyst systems for Pd-catalyzed organic reactions without the laborious conventional catalyst recovery and redispersion processes. The SNFs-Pd catalyst system exhibited high activity and high selectivity in single and successive Heck coupling reactions; and a reusability as high as 90% was still possible in the 20th cycle. This mussel-inspired approach is highly versatile and can be applied to laboratory chemical reactors in different shapes, sizes, and configurations to scale up the nanocatalyst applications. Furthermore, the general utility of the chemistry involved allows this surface modification technique to apply to other supported noble metal (e.g., Ag, Au, and Pt) catalysts, thereby increasing the usability and the performance of nanocatalyst systems.
A novel bisoxazoline/Pd composite microsphere: A highly active catalyst for Heck reactions
Wang, Junke,Zong, Yingxiao,Yue, Guoren,Hu, Yulai,Wang, Xicun
, p. 76285 - 76290 (2015/09/28)
A novel bisoxazoline/Pd microsphere catalyst was successfully prepared. The structure of the solid catalyst was characterized by SEM, TGA and FT-IR. The catalyst exhibits excellent activity for the Heck reaction. Moreover, the catalyst shows outstanding stability and reusability, can be recovered simply and effectively and reused six times without any activity decrease.
Ionic liquid immobilized palladium nanoparticle-Graphene hybrid as active catalyst for heck reaction
Srivastava, Vivek
, p. 67 - 72 (2015/04/14)
We engineered, graphene based Pd-Nano composites (Pd/RGO) and tested them to catalyze the Heck reaction in [bmim] NTf2 solvent system. High yield, easy product isolation, recycling of the catalytic system and ligand free approach are the main outcomes of this proposed protocol. The proposed protocol was further exploited for the successful synthesis of 3-styryl coumarins in good yield.
Template-directed synthesis of palladium(II) sulfonate-NHC complexes and catalytic studies in aqueous Mizoroki-Heck reactions
Yuan, Dan,Teng, Qiaoqiao,Huynh, Han Vinh
, p. 1794 - 1800 (2014/05/06)
Oxidation of easily accessible thiolato-functionalized dinuclear Pd(II) NHC complexes 1-3 by Oxone gave rise to sulfonate-NHC complexes 4-6. This represents the first template-directed approach to NHC complexes bearing sulfonate functions, where the sulfu
Poly(ethylene glycol) as reaction medium for mild Mizoroki-Heck reaction in a ball-mill
Declerck, Valerie,Colacino, Evelina,Bantreil, Xavier,Martinez, Jean,Lamaty, Frederic
, p. 11778 - 11780 (2013/01/15)
Phosphine-free palladium-catalyzed Mizoroki-Heck reaction was performed using ball-milling in polyethylene glycol under mild conditions. Good to excellent yields of coupling products were obtained. This activation technique also allowed the concomitant fo
