Coordination chemistry of arylhydrazones of methylene active compounds

Design, synthesis and anticancer evaluation of novel arylhydrazones of active methylene compounds

Nerve growth factor (NGF) and its receptor, tropomyosin kinase receptor kinase type A (TrkA) is emerging as an important target for Glioblastoma (GBM) treatment. TrkA is the cancer biomarker majorly involved in tumor invasion and migration into nearby normal tissue. However, currently, available Trk inhibitors exhibit many adverse effects in cancer patients, thus demanding a novel class of ligands to regulate Trk signaling. Here, we exploited the role of TrkA (NTRK1) expression from the 651 datasets of brain tumors. RNA sequence analysis identified overexpression of NTRK1 in GBM, recurrent GBM as well in Oligoastrocytoma patients. Also, TrkA expression tends to increase over the higher grades of GBM. TrkA protein targeting hydrazone derivatives, R48, R142, and R234, were designed and their mode of interaction was studied using molecular docking and dynamic simulation studies. Ligands' stability and binding assessment reveals R48, 2 2-(2-(2-hydroxy-4-nitrophenyl) hydrazineylidene)-1-phenylbutane-1,3-dione, as a potent ligand that interacts well with TrkA's hydrophobic residues, Ile, Phe, Leu, Ala, and Val. R48- TrkA exhibits stable binding potentials with an average RMSD value <0.8 nm. R48 obeyed Lipinski's rule of five and possessed the best oral bioavailability, suggesting R48 as a potential compound with drug-likeness properties. In-vitro analysis also revealed that R48 exhibited a higher cytotoxicity effect for U87 GBM cells than TMZ with the IC50 value of 68.99 μM. It showed the lowest percentage of cytotoxicity to the non-cancerous TrkA expressing MEF cells. However, further SiRNA analysis validates the non-specific binding of R48, necessitating structural alteration for the development of R48-based TrkA inhibitor for GBM therapeutics.

Halogen Bonding in the Decoration of Secondary Coordination Sphere of Zinc(II) and Cadmium(II) Complexes: Catalytic Application in Cycloaddition Reaction of CO2 with Epoxides

Three new zinc(II) complexes [Zn(H2L3)2(H2O)3] (Zn2), [Zn(H3L2a)(H2O)3]n (Zn3) (H3L2a = 2,4-diiodo-5-(2-(2,4,6-trioxotetrahydropyrimidin-5(2H)-ylidene)hydrazineyl)isophthalate) and [Zn(HL4)(DMF)(H2O)]n (Zn4) were synthesized by the reaction of Zn(II) salts with 5-(2-(2,4-dioxopentan-3-ylidene)hydrazineyl) isophthalic acid (H3L3), 2,4,6-triiodo-5-(2-(2,4,6-trioxotetrahydropyrimidin-5(2H)-ylidene)hydrazineyl) isophthalic acid (H5L2) (in the presence of NH2OH·HCl) and 5-(2-(2,4-dioxopentan-3-ylidene)hydrazineyl)-2,4,6-triiodoisophthalic acid (H3L4), respectively. According to the X-ray structural analysis, the intramolecular resonance-assisted hydrogen bond ring remains intact, with N···O distances of 2.562(5) and 2.573(5) Å in Zn2, 2.603(6) Å in Zn3, and 2.563(8) Å in Zn4. In the crystal packing of Zn3, the cooperation of I···O and I···I types of halogen bonds between tectons leads to a one-dimensional supramolecular polymer, while I···O interactions aggregate 1D chains of coordination polymer Zn4. These new complexes (Zn2, Zn3, and Zn4) and known [Zn(H3L1)(H2O)2]n (Zn1) (H3L1 = 5-(2-(2,4,6-trioxotetrahydropyrimidin-5(2H)-ylidene) hydrazineyl)isophthalate), {[Zn(H3L1)(H2O)3]·3H2O}n (Zn5), [Cd(H3L1)(H2O)2]n (Cd1), {[Cd(HL3)(H2O)2(DMF)]·H2O}n (Cd2), [Cd(H3L3)]n (Cd-3), {[Cd2(μ-H2O)2(μ-H2L4)2(H2L4)2]·2H2O}n (Cd4), and {[Cd(H3L1)(H2O)3]·4H2O}n (Cd5) were tested as catalysts in the cycloaddition reaction of CO2 with epoxides in the presence of tetrabutylammonium halides as the cocatalyst. The halogen-bonded catalyst Zn4 is the most efficient one in the presence of tetrabutylammonium bromide by affording a high yield (85-99%) of cyclic carbonates under solvent-free conditions after 48 h at 40 bar and 80 °C.

Synthesis, structural characterization, antioxidant, cytotoxic activities and docking studies of schiff base Cu(II) complexes

By combining hydrazide with 2-Acetylpyridine, a hydrazone ligand (HL) was successfully created. Several copper (II) salts have been used to create three copper (II) hydrazone complexes (acetate, sulphate, and chloride). The hydrazide ligand and its copper (II) complexes (1-3) were studied via variety of analytical techniques, including elemental analysis, electronic, infrared, UV-vis Spectrum, XRD study, thermal analysis, also molar conductivity amounts. The spectrum results indicate that in all complexes, the ligand exhibits monobasic tridentate behavior. Octahedral geometries were present in all metal complexes. The Coats-Redfern equations were used to compute and describe the dynamics properties of several steps of TGA (Ea, A, ΔH*, ΔS*, and ΔG*). Calculations using the density functional theory (DFT) were done at the molecular studio software toward examine ligands agent's and its complexes' best structures. The MCF-7 in addition to HepG-2 cell lines was resistant to tumor-inducing effects of the copper (II) chelates. The in vitro antioxidant capacities of all complexes have been estimated via DPPH free radical scavenger assays. Furthermore, zones of inhibition length accustomed to test antimicrobial effect of particular complexes in vitro towards Staphylococcus aureus (Gram positive bacteria) E. coli (Gram negative bacteria). Both absorption spectra and viscosity measurements in calf thymus DNA binding have been used to study the complexes. In order to explore docking research of copper (II) chelates, the crystallographic construction of the SARS-active CoV-2's site protein (PDB ID:6XBH) was used (COVID-19) and breast cancer distorted (PDB ID: 3hb5).

Synthesis and crystal structure of catena-poly[[[aqua-{2-[(E)-(1-cyano-2-imino-2-meth-oxy-ethyl-idene)hydrazin-yl]benzene-sulfonato}-sodium]-di-μ-aqua] dihydrate]

In the polymeric title compound, {[Na(C₁₀H₉N₄O₄S)(H₂O)₃]·2H₂O} _n , sixfold coordinated Na⁺ cations are linked into a chain parallel to [010] by sharing common water mol-ecules. Next to the four bridging water mol-ecules, each Na⁺ cation of the chain is bonded to the O atom of a terminal water mol-ecule and an O atom of the SO₃ ^- group of the sulfonate anion. Classical O-H⋯O, O-H⋯N and N-H⋯O hydrogen bonds and additional π-π inter-actions connect these chains into a three-dimensional network.

Iron(III) Arylhydrazone Complexes Immobilized on Amine-Functionalized Mesoporous Silica: Catalysts for the Valorization of Biomass-Derived Furfuryl Alcohol

The aquasoluble Fe^III complexes [Fe(H₂ O)₃ (L¹ )] ⋅ 4H₂ O (Fe1) and [Fe(H₂ O)₃ (L² )] ⋅ 3H₂ O (Fe2), bearing the basic forms of 5-chloro-3-(2-(4,4-dimethyl-2,6-dioxocyclohexylidene)hydrazinyl)-2-hydroxy-benzenesulfonic acid (H₃ L¹ ) and 3-(2-(2,4-dioxopentan-3-ylidene)hydrazinyl)-2-hydroxy-5-nitrobenzenesulfonic acid (H₃ L² ), were incorporated for the first time into amine-functionalized SBA-15 support via an impregnation method. The successful preparation of the composites was confirmed by Fourier-Transform Infrared spectroscopy (FT-IR), powder X-ray diffraction (XRD), scanning electron microscope (SEM/EDS), transmission electron microscopy (TEM), elemental analysis, and nitrogen adsorption-desorption isotherms. The resulting Fe1@aptesSBA-15 and Fe2@aptesSBA-15 composites were tested as the first SBA-15-based heterogeneous catalysts for the conversion of furfuryl alcohol under mild reaction conditions (80 to 100 °C) and with an environmentally friendly oxidant (TBHP, 70 % aq. sol. with 1 : 1 oxidant/substrate molar ratio). The influence of various factors, such as reaction time, amounts of oxidant and catalyst, was investigated. The reaction time can be fairly reduced by adopting a microwave-assisted method allowing it to reach complete conversion after 0.25 h, in the absence of any added solvent or additive. Under these conditions, a vigorous furfuryl alcohol polymerization process occurred, with furfural as a by-product. Recycling studies were carried out for Fe2@aptesSBA-15 and after four consecutive runs, the overall conversion of furfuryl alcohol remained high (≥99 %), without an appreciable change in the obtained yield.

Peroxidative Oxidation of Cyclohexane Using 3d Metal Complexes with Hydrazone-Derived Ligands as Catalysts: Exploring (Un)Conventional Conditions

Two tetranuclear and two mononuclear Cu(II) complexes with arylhydrazones of malononitrile derived ligands (compounds 1–2 and 3–4, respectively), one trinuclear Co(II/III) complex with an arylhydrazone of acetoacetanilide (5) and one tetranuclear Zn(II) complex of 3-(2-carboxyphenyl-hydrazone)pentane-2,4-dione (6) were screened as potential catalysts in the peroxidative oxidation of cyclohexane by aqueous H2O2 in acetonitrile. The best results were attained in the presence of pyrazine-2-carboxylic acid (PCA) with 1 (26% yield, TON = 52.0) and with 2 (24%, TON = 48.0) after 4 h at 40 °C. In the presence of complexes 5 and 6, no oxygenated products were detected in the studied conditions. The employment of non-conventional conditions like supercritical carbon dioxide (scCO2) as reaction medium or microwave (MW) irradiation was assessed for complexes 1 and 2. After 6 h in acetonitrile–scCO2, at 50 °C and with HNO3 as promoter, only 17% yield was achieved using 1 as catalyst, and 21% using 2. Total yields of oxygenates up to 14 (with 1) and 13% (2) and TOFs of 56.0 and 52.0 h−1, respectively, were obtained working under MW irradiation at 70 °C and for the much shorter time of 0.5 h.

Crystal structure and Hirshfeld surface analysis of a new polymorph of (E)-2-(4-bromophenyl)-1-[2,2-dibromo-1-(3-nitrophenyl)ethenyl]diazene

The a new polymorph of the title compound is reported in which the C—H⋯O hydrogen bonds and π-π stacking inter­actions link mol­ecules into the layers in the crystal.

A new polymorph of the title compound, C₁₄H₈Br₃N₃O₂, (form-2) was obtained in the same manner as the previously reported form-1 [Akkurt et al. (2022 ▸). Acta Cryst. E78, 732–736]. The structure of the new polymorph is stabilized by a C—H⋯O hydrogen bond that links mol­ecules into chains. These chains are linked by face-to-face π–π stacking inter­actions, resulting in a layered structure. Short inter-mol­ecular Br⋯O contacts and van der Waals inter­actions between the layers aid in the cohesion of the crystal packing. In the previously reported form-1, C—H⋯Br inter­actions connect mol­ecules into zigzag chains, which are linked by C—Br⋯π inter­actions into layers, whereas the van der Waals inter­actions between the layers stabilize the crystal packing of form-2. Hirshfeld mol­ecular surface analysis was used to compare the inter­molecular inter­actions of the polymorphs.

Crystal structure and Hirshfeld surface analysis of (E)-2-(4-bromo-phen-yl)-1-[2,2-di-bromo-1-(4-nitro-phen-yl)ethen-yl]diazene

The mol-ecule of the title compound, C₁₄H₈Br₃N₃O₂, consists of three almost planar groups: the central di-bromo-ethenyldiazene fragment and two attached aromatic rings. The mean planes of these rings form dihedral angles with the plane of the central fragment of 26.35 (15) and 72.57 (14)° for bromine- and nitro-substituted rings, respectively. In the crystal, C-H⋯Br inter-actions connect mol-ecules, generating zigzag C(8) chains along the [100] direction. These chains are linked by C-Br⋯π inter-actions into layers parallel to (001). van der Waals inter-actions between the layers aid in the cohesion of the crystal packing. The most substantial contributions to crystal packing, according to a Hirshfeld surface analysis, are from Br⋯H/H⋯Br (20.9%), C⋯H/H⋯C (15.2%), O⋯H/H⋯O (12.6%) and H⋯H (11.7%) contacts.

Water-soluble Al(iii), Fe(iii) and Cu(ii) formazanates: synthesis, structure, and applications in alkane and alcohol oxidations

The synthesis, structure and catalytic performance of water-soluble Al(iii), Fe(iii) and Cu(ii) formazanates in the oxidation of cyclohexane and cyclohexanol to the coresponding organic products are reported.

Halogen bonding in cadmium(II) MOFs: its influence on the structure and on the nitroaldol reaction in aqueous medium

A solvothermal reaction of Cd(II) with the dicarboxyl-functionalized arylhydrazone pro-ligands, 5-(2-(2,4,6-trioxotetrahydro-pyrimidin-5(2H)-ylidene)hydrazineyl)isophthalic acid (H₅L¹) and 5-(2-(2,4-dioxopentan-3-ylidene)hydrazineyl)isophthalic acid (H₃L²), or their halogen bond donor centre(s) decorated analogs 2,4,6-triiodo-5-(2-(2,4,6-trioxotetrahydropyrimidin-5(2H)-ylidene)hydrazineyl)isophthalic acid (H₅L³) and 5-(2-(2,4-dioxopentan-3-ylidene)hydrazineyl)-2,4,6-triiodoisophthalic acid (H₃L⁴), leads to the formation of known [Cd(H₃L¹)(H₂O)₂]_n (1) and new {[Cd(HL²)(H₂O)₂(DMF)]·H₂O}_n (2), [Cd(H₃L³)]_n (3) and {[Cd₂(μ-H₂O)₂(μ-H₂L⁴)₂(H₂L⁴)₂]·2H₂O}_n (4) coordination compounds, respectively. The aggregation of mononuclear units via Cd-OC and Cd-OH₂ coordination and C_Ar-I⋯I types of intramolecular halogen bonds lead to a dinuclear tecton 4. Both C_Ar-I⋯O and C_Ar-I⋯I types of intermolecular halogen bonds play a fundamental role in the supramolecular architectures of the obtained metal-organic frameworks 3 and 4. Theoretical (DFT) calculations confirmed the presence of the C_Ar-I⋯O and C_Ar-I⋯I halogen bonds in 3 and 4 and allowed their characterisation. The formation of intermolecular noncovalent interactions between the attached iodine substituents to the hydrazone ligands and polar solvent (water or methanol) molecules promoted, at least in part, the solubility of the corresponding complexes (3 and 4), which act as homogeneous catalyst precursors in the Henry reaction between aldehydes and nitroethane. The corresponding β-nitroalkanol products were obtained in good yields (66-79%) and with good diastereoselectivity (threo/erythro ca. 72 : 28) in water at room temperature.

Crystal structure and Hirshfeld surface analysis of (E)-1-(2,6-di-chloro-phen-yl)-2-(2-nitro-benzyl-idene)hydrazine

In the title compound, C13H9Cl2N3O2, the 2,6-di-chloro-phenyl ring and the nitro-substituted benzene ring form a dihedral angle of 21.16 (14)°. In the crystal, face-to-face π-π stacking inter-actions occur along the a-axis direction between the centroids of the 2,6-di-chloro-phenyl ring and the nitro-substituted benzene ring. Furthermore, these mol-ecules show intra-molecular N-H⋯Cl and C-H⋯O contacts and are linked by inter-molecular N-H⋯O and C-H⋯Cl hydrogen bonds, forming pairs of hydrogen-bonded mol-ecular layers parallel to (20). The Hirshfeld surface analysis of the crystal structure indicates that the most important contributions to the crystal packing are from H⋯H (23.0%), O⋯H/H⋯O (20.1%), Cl⋯H/H⋯Cl (19.0%), C⋯C (11.2%) and H⋯C/C⋯H (8.0%) inter-actions.

Crystal structure and Hirshfeld surface analysis of (E)-4-{2,2-di-chloro-1-[(3,5-di-methyl-phen-yl)diazen-yl]ethen-yl}-N,N-di-methyl-aniline

In the title compound, C18H19Cl2N3, the planes of the benzene rings subtend a dihedral angle of 77.07 (10)°. In the crystal, mol-ecules are associated into inversion dimers via short Cl⋯Cl contacts [3.3763 (9) Å]. A Hirshfeld surface analysis indicates that the most important contact percentages for the different types of inter-actions are H⋯H (43.9%), Cl⋯H/H⋯Cl (22.9%), C⋯H/H⋯C (20.8%) and N⋯H/H⋯N (8.0%).

Crystal structure and Hirshfeld surface analysis of 4-{2,2-di-chloro-1-[(E)-(4-fluoro-phen-yl)diazen-yl]ethen-yl}-N,N-di-methyl-aniline

The dihedral angle between the two aromatic rings of the title compound is 64.12 (14)°. The crystal structure is stabilized by a short Cl⋯H contact, C—Cl⋯π and van der Waals inter­actions.

In the title compound, C₁₆H₁₄Cl₂FN₃, the dihedral angle between the two aromatic rings is 64.12 (14)°. The crystal structure is stabilized by a short Cl⋯H contact, C—Cl⋯π and van der Waals inter­actions. The Hirshfeld surface analysis and two-dimensional fingerprint plots show that H⋯H (33.3%), Cl⋯H/H⋯Cl (22.9%) and C⋯H/H⋯C (15.5%) inter­actions are the most important contributors towards the crystal packing.

Crystal structure and Hirshfeld surface analysis of (E)-3-(benzyl-idene-amino)-5-phenyl-thia-zolidin-2-iminium bromide

The central thia-zolidine ring of the title salt, C16H16N3S+·Br-, adopts an envelope conformation, with the C atom bearing the phenyl ring as the flap atom. In the crystal, the cations and anions are linked by N-H⋯Br hydrogen bonds, forming chains parallel to the b-axis direction. Hirshfeld surface analysis and two-dimensional fingerprint plots indicate that the most important contributions to the crystal packing are from H⋯H (46.4%), C⋯H/H⋯C (18.6%) and H⋯Br/Br⋯H (17.5%) inter-actions.

Role of substituents on resonance assisted hydrogen bonding vs. intermolecular hydrogen bonding

Resonance assisted hydrogen bond (RAHB) ring can be weakened/opened by a strong electron-donor (ED) group.

Synthesis, DNA/BSA binding studies and in vitro biological assay of nickel(II) complexes incorporating tridentate aroylhydrazone and triphenylphosphine ligands

Two new nickel (II) triphenylphosphine complexes derived from tridentate aroylhydrazone ligands [H2L1 = 2-hydroxy-3-methoxybenzylidene)benzohydrazone and H2L2 = N'-(2-hydroxy-3-methoxybenzylidene)-2-hydroxybenzoylhydrazone] and triphenylphosphine were prepared and their molecular structures were determined by single crystal X-ray diffraction analysis. Both nickel(II) complexes showed slightly distorted square planar geometry with one tridentate aroylhydrazone ligand coordinated through ONO donor atoms and one triphenylphosphine ligand coordinated to the nickel center through the phosphorus atom. DNA interaction studies indicated that both complexes possessed higher affinity to herring sperm DNA (HS-DNA) than the corresponding free aroylhydrazone ligand. Molecular docking investigations showed that both complexes could bind to DNA through intercalation of the phenyl rings between adjacent base pairs in the double helix. Meanwhile, bovine serum albumin (BSA) binding studies revealed the complexes could effectively interact with BSA and change the secondary structure of BSA. Further pharmacological evaluations of the synthesized complexes by in vitro antioxidant assays demonstrated high antioxidant activity against NO· and O2˙- radicals. The anticancer activity of each complex was assessed through in vitro cytotoxicity assays (CCK-8 kit) toward A549 and MCF-7 cancer cell and normal L-02 cell lines. Significantly, the Ni(II) complex derived from H2L1 ligand was found to be more effective cytotoxic toward MCF-7cancerous cell with the IC50 value equaled 9.7 μM, which showed potent cytotoxic activity over standard drug cisplatin. AbbreviationsA549human lung carcinoma cellBSAbovine serum albuminCCK-8Cell Counting Kit-8DFTdensity functional theoryDNAdeoxyribonucleic acidDPPH˙2,2-diphenyl-1-picrylhydrazylH2L12-hydroxy-3-methoxybenzylidene)benzohydrazone N'-(2-hydroxy-3-methoxybenzylidene)-2-hydroxybenzoylhydrazoneH2L2N'-(2-hydroxy-3-methoxybenzylidene)-2-hydroxybenzoylhydrazoneHOMOhighest occupied molecular orbitalIC50the 50% activityL-02human normal liver cellLOMOlowest unoccupied molecular orbital (LUMO)MCF-7human breast carcinoma cellNO˙nitric oxideO2˙-superoxide anionSODsuperoxide dismutaseCommunicated by Ramaswamy H. Sarma.

Crystal structure and Hirshfeld surface analysis of (E)-4-{[2,2-di-chloro-1-(4-meth-oxy-phen-yl)ethen-yl]diazen-yl}benzo-nitrile

In the title compound, C16H11Cl2N3O, the 4-meth-oxy-substituted benzene ring makes a dihedral angle of 41.86 (9)° with the benzene ring of the benzo-nitrile group. In the crystal, mol-ecules are linked into layers parallel to (020) by C-H⋯O contacts and face-to-face π-π stacking inter-actions [centroid-centroid distances = 3.9116 (14) and 3.9118 (14) Å] between symmetry-related aromatic rings along the a-axis direction. A Hirshfeld surface analysis indicates that the most important contributions to the crystal packing are from Cl⋯H/H⋯Cl (22.8%), H⋯H (21.4%), N⋯H/H⋯N (16.1%), C⋯H/H⋯C (14.7%) and C⋯C (9.1%) inter-actions.

Crystal structure and Hirshfeld surface analysis of (E)-3-[(4-fluoro-benzyl-idene)amino]-5-phenyl-thia-zolidin-2-iminium bromide

In the cation of the title salt, C16H15FN3S+·Br-, the phenyl ring is disordered over two sets of sites with a refined occupancy ratio of 0.503 (4):0.497 (4). The mean plane of the thia-zolidine ring makes dihedral angles of 13.51 (14), 48.6 (3) and 76.5 (3)° with the fluoro-phenyl ring and the major- and minor-disorder components of the phenyl ring, respectively. The central thia-zolidine ring adopts an envelope conformation. In the crystal, centrosymmetrically related cations and anions are linked into dimeric units via N-H⋯Br hydrogen bonds, which are further connected by weak C-H⋯Br hydrogen bonds into chains parallel to [110]. Hirshfeld surface analysis and two-dimensional fingerprint plots indicate that the most important contributions to the crystal packing are from H⋯H (44.3%), Br⋯H/H⋯Br (16.8%), C⋯H/H⋯C (13.9%), F⋯H/H⋯F (10.3%) and S⋯H/H⋯S (3.8%) inter-actions.

Cyanosilylation of Aldehydes Catalyzed by Ag(I)- and Cu(II)-Arylhydrazone Coordination Polymers in Conventional and in Ionic Liquid Media

The novel Ag(I) and Cu(II) coordination polymers [Ag(μ3-1κO;2:3κO′;4κN-HL)]n∙n/2H2O (1) and [Cu(en)2(μ-1κO;2κN-L)]n∙nH2O (2) [HL− = 2-(2-(1-cyano-2-oxopropylidene)hydrazinyl)benzene sulfonate] were synthesized and characterized by IR and ESI-MS spectroscopies, elemental and single crystal X-ray diffraction analyses. Compounds 1 and 2 as well as the already known complex salt [Cu(H2O)2(en)2](HL)2 (3) have been tested as homogenous catalysts for the cyanosilylation reaction of different aldehydes with trimethylsilyl cyanide, to provide cyanohydrin trimethylsilyl ethers. Coordination polymer 2 was found to be the most efficient one, with yields ranging from 76 to 88% in methanol, which increases up to 99% by addition of the ionic liquid [DHTMG][L-Lactate].

Copper(II) Complexes of Arylhydrazone of 1H-Indene-1,3(2H)-dione as Catalysts for the Oxidation of Cyclohexane in Ionic Liquids

The copper(II) complexes [CuL(H2O)2]∙H2O (1) and [CuL(dea)] (2) [L = 2-(2-(1,3-dioxo-1H-inden-2(3H)-ylidene)hydrazinyl)benzenesulfonate, dea = diethanolamine] were applied as catalysts in the peroxidative (with tert-butyl-hydroperoxide or hydrogen peroxide) conversion of cyclohexane to cyclohexanol and cyclohexanone, either in acetonitrile or in any of the ionic liquids [bmim][NTf2] and [hmim][NTf2] [bmim = 1-butyl-3-methylimidazolium, hmim = 1-hexyl-3-methylimidazolium, NTf2 = bis(trifluoromethanesulfonyl) imide]. Tert-butyl-hydroperoxide led to better product yields, as compared to H2O2, with a selectivity directed towards cyclohexanone. The ILs showed a better performance than the conventional solvent for the copper complex 1. No catalytic activity was observed for 2 in the presence of an IL.