Synthesis and structures of copper complexes bearing unsymmetric derivatives of ( R,R )‐1,2‐diaminocyclohexane: An efficient catalyst for asymmetric Henry reaction

2019 ◽  
Vol 33 (7) ◽  
Author(s):  
Juhyun Cho ◽  
Min Kyung Chun ◽  
Saira Nayab ◽  
Jong Hwa Jeong
2019 ◽  
Author(s):  
Chem Int

A series of novel 1, 3, 4-oxadiazole analogues was synthesized from cyclization of hydrazones of substituted 1-ethyl-1,4-dihydro-7-methyl-4-oxo-1,8-naphthyridine-3-carbohydrazides were prepared from nalidixic acid. The structures of synthesized oxadiazole derivatives and their copper complexes were elucidated on the basis of FTIR, elemental analyses, 1H-NMR and atomic absorption spectral analysis. It was observed from spectral data that metal ligand ratio was 1:1 in all copper complexes and they were bidentate, coordination was found to be done through oxygen of 4-oxo group and nitrogen of oxadiazole ring. The synthesized compounds were further evaluated with biological activities and compared with parent hydrazones. Copper complexes possess antibacterial and antifungal activities better than the oxadiazoles while they have better antioxidant activity then copper complexes. Parent hydrazones were better in all biological activities than synthesized oxadiazoles.


2014 ◽  
Vol 4 (7) ◽  
pp. 1997-2005 ◽  
Author(s):  
R. Oost ◽  
J. Rong ◽  
A. J. Minnaard ◽  
S. R. Harutyunyan

New derivatives of copper complexes of Josiphos family ligands have been prepared and studied in asymmetric catalytic addition of Grignard reagents to enones, enoates and aromatic ketones.


2018 ◽  
Vol 54 (8) ◽  
pp. 892-895 ◽  
Author(s):  
E. W. Dahl ◽  
H. T. Dong ◽  
N. K. Szymczak

A series of copper complexes bearing new 6-substituted tris(2-pyridylmethyl)amine ligands (LR) appended with NH(p-R-C6H4) groups (R = H, CF3, OMe) were prepared.


1992 ◽  
Vol 15 (2) ◽  
pp. 130-133
Author(s):  
Tarek M. Ibrahim ◽  
Ahmed A. Shabana ◽  
Hamdy A. Hammad

1976 ◽  
Vol 29 (4) ◽  
pp. 767 ◽  
Author(s):  
M Das ◽  
SE Livingstone ◽  
JH Mayfield ◽  
DS Moore ◽  
N Saha

Dipole moments have been determined by static polarization measurements for some iron(111), ruthenium(111), rhodium(111), nickel(11), palladium(11), platinum(11), copper(11) and zinc(11) complexes of fluorinated monothio-β-diketones RC(SH)=CHCOCF3. The moments indicate a facial-octahedral configuration for the iron, ruthenium and rhodium complexes, a cis-square-planar configuration for the nickel, palladium and platinum complexes, and a tetrahedral configuration for the zinc complexes. The copper complexes have moments 0.5-1.0 D lower than the mean value for the corresponding nickel, palladium and platinum complexes; this lowering of the moment is attributed to significant distortion from the square-planar towards the tetrahedral configuration. The dipole moments of the square-planar and octahedral complexes decrease if the R groups are arranged in the order: p-MeC6H4 ≥ 2-thienyl > β-naphthyl > m-MeC6H4 > Ph > Pr? > Bui > Me > m-ClC6H4 > m-BrC6H4 > p-FC6H4 > p-ClC6H4 > p-BrC6H4 > m,p-Cl2C6H3.


2016 ◽  
Vol 12 ◽  
pp. 863-873 ◽  
Author(s):  
Shaojin Gu ◽  
Jiehao Du ◽  
Jingjing Huang ◽  
Huan Xia ◽  
Ling Yang ◽  
...  

A series of copper complexes (3–6) stabilized by 1,2,3-triazole-tethered N-heterocyclic carbene ligands have been prepared via simple reaction of imidazolium salts with copper powder in good yields. The structures of bi- and trinuclear copper complexes were fully characterized by NMR, elemental analysis (EA), and X-ray crystallography. In particular, [Cu2(L2)2](PF6)2 (3) and [Cu2(L3)2](PF6)2 (4) were dinuclear copper complexes. Complexes [Cu3(L4)2](PF6)3 (5) and [Cu3(L5)2](PF6)3 (6) consist of a triangular Cu3 core. These structures vary depending on the imidazolium backbone and N substituents. The copper–NHC complexes tested are highly active for the Cu-catalyzed azide–alkyne cycloaddition (CuAAC) reaction in an air atmosphere at room temperature in a CH3CN solution. Complex 4 is the most efficient catalyst among these polynuclear complexes in an air atmosphere at room temperature.


2013 ◽  
Vol 91 (4) ◽  
pp. 300-306 ◽  
Author(s):  
Lalthazuala Rokhum ◽  
Ghanashyam Bez

Over the last few decades, the fast-growing development of polymer supported reagents has led to the synthesis of a variety of reagents on solid support. Some of the major advantages of using such reagents are that they are less hygroscopic, easy to recover, and can be recycled. Here, we have demonstrated that in situ generated ethyl acrylate conjugated polystyryl-diphenylphosphine (PDPP–EA) derived from the reaction of a mixture of polystyryl-diphenylphosphine and ethyl acrylate in a stoichiometric ratio can efficiently catalyze the synthesis of β-nitroalcohols from the reaction of aldehydes and nitroalkanes under solvent-free conditions (SolFC).


1968 ◽  
Vol 21 (7) ◽  
pp. 1781 ◽  
Author(s):  
RKY Ho ◽  
SE Livingstone

Four new fluorinated monothio-β-diketones of general formula RC(SH)=CH- COCF3 have been prepared; they are: l,l,l-trifluoro-4-mercapto-4-(4-methylphenyl)but-3-en-2-one (R = p-methylphenyl), 1,1,1-trifluoro-4-mercapto-4- (4-methoxyphenyl)but-3-en-2-one (R = p-methoxyphenyl), 4-(4-bromophenyl)-l,l,l- trifluoro-4-mercaptobut-3-en-2-one (R = p-bromophenyl), and l,l,l-trifluoro-4- (2-furyl)-4-mercaptobut-3-en-2-one (R = 2-furyl). Their nickel complexes, which are brown and diamagnetic, yield stable high-spin bis-pyridine adducts. When R = p-MeC6H4, p-MeOC6H4, or p-BrC6H4 the ligand yields both copper(1) and copper(11) complexes but when R = 2-furyl only a copper(11) complex is obtained. Infrared data indicate that in the copper(1) complexes the ligand is coordinated through the sulphur atom only.


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