22865-50-5Relevant articles and documents
Homoleptic and heteroleptic Zn(ii) selone catalysts for thioetherification of aryl halides without scrubbing oxygen
Vaddamanu, Moulali,Velappan, Kavitha,Prabusankar, Ganesan
, p. 3574 - 3583 (2020/03/17)
Five new mononuclear tetra-coordinated zinc(ii) selones, [Zn(L1)2Cl2] (1), [Zn(L1)2Br2] (2), [{Zn(L2)4}{BF4}2] (3), [{Zn(L2)4}{ClO4}2] (4), and [Zn(L2)2Br2] (5), have been isolated from a one-pot reaction between the corresponding zinc(ii) salt and selone ligand, 1-methyl 3-naphthylmethylimidazoline-2-selone (L1) or 1-isopropyl 3-methylimidazoline-2-selone (L2). All these complexes were characterized by CHN analysis, FT-IR, NMR studies, and single-crystal X-ray crystallography techniques. The Zn(ii) center in 1-5 exhibits a distorted tetrahedral geometry. Besides, 1-5 were employed as catalysts in the thioetherification of aryl halides. The first zinc(ii) catalyst-mediated thioetherification of aryl halides without scrubbing oxygen was demonstrated. Catalysts 1-5 are highly active towards the cross-coupling reaction between aryl halides and thiophenols. The catalytic ability of 1-5 was explored in THF, toluene, and CH3CN solvents with different bases such as K2CO3, Cs2CO3, and NaOtBu. Interestingly, the zinc(ii) center attached to two selone ligands is much more catalytically active than that attached to four selone ligands.
CuMoO4 Bimetallic Nanoparticles, An Efficient Catalyst for Room Temperature C?S Cross-Coupling of Thiols and Haloarenes
Panigrahi, Reba,Sahu, Santosh Kumar,Behera, Pradyota Kumar,Panda, Subhalaxmi,Rout, Laxmidhar
, p. 620 - 624 (2019/12/27)
CuII catalyst is less efficient at room temperature for C?S cross-coupling. C?S cross-coupling by CuII catalyst at room temperature is not reported; however, doping of copper with molybdenum metal has been realized here to be more efficient for C?S cross-coupling in comparison to general CuII catalyst. The doped catalyst CuMoO4 nanoparticle is found to be more efficient than copper. The catalyst works under mild conditions without any ligand at room temperature and is recyclable and effective for a wide range of thiols and haloarenes (ArI, ArBr, ArF) from milligram to gram scale. The copper-based bimetallic catalyst is developed and recognized for C?S cross-coupling of haloarenes with alkyl and aryl thiols.
Pd (II) immobilized on clinoptilolite as a highly active heterogeneous catalyst for ullmann coupling-type s-arylation of thiols with aryl halides
Alizadeh, Abdollah,Khalilzadeh, Mohammad A.,Alipour, Eskandar,Zareyee, Daryoush
, p. 657 - 666 (2020/08/24)
Background: There are a number of protocols for Ullmann coupling–type S-arylation reactions, many of them suffer from the use of homogenous and often corrosive catalyst, cumbersome workup procedures, and long reaction times. Besides, many of these reagents are expensive and non-recoverable, leading to the generation of a large amount of toxic waste particularly when large-scale applications are considered. Objective: The aim of this study was to prepare a new Pd catalyst bonded on the surface of zeolite as a heterogeneous catalyst. Methods: A heterogeneous palladium catalyst has been prepared by immobilizing Pd ions on Clinoptilolite. This novel developed heterogeneous catalyst was thoroughly examined for Ullmann coupling–type S-arylation reaction using different bases, solvents and 0.003 mg of the catalyst. The structural and morphological characterizations of the catalyst were carried out using XRD, TGA, BET and TEM techniques. Results: Highly efficient heterogeneous palladium catalyst has been developed by immobilizing Pd ions on Clinoptilolite, as one of the most abundant naturally occurring zeolites for Ullmann S-arylation. By using this method, we provide an efficient way to a wide variety of substituted thiolic compounds. Moreover, the catalyst is easily recovered using simple filtration and reused for 5 consecutive runs. Conclusion: In this effort, we developed a new Pd catalyst bonded on the surface of zeolite as a substrate to prepare the heterogeneous catalyst. We demonstrate that this novel catalyst offers reliable and convincing data that may offer a valuable application in further developing the science and technology of Ullmann reaction protocols and allied industries. Additionally, the catalyst was reusable and kept its high activities over a number of cycles.
