51437-25-3

Upstream product

• 75-91-2 tert.-butylhydroperoxide 
• 110-83-8 cyclohexene 
• 64-19-7 acetic acid 
• 1521-51-3 rac-3-bromocyclohexene 
• 75-07-0 acetaldehyde 

Downstream Products

• 930-68-7 cyclohexenone 
• 75-65-0 tert-butyl alcohol 
• 822-67-3 Cyclohex-2-enol 

Relevant academic research and scientific papers

Windmill-type mixed-metal clusters containing Schiff-base ligands as an efficient catalyst for cyclohexene oxidation

Two new mixed-metal clusters {CuM2(H2O)2[Cu(C14H16N2O3)Cl]6}·H2O (M = Mn 1, Zn 2) based on Schiff-base ligands were designed and synthesized by the reaction of 1,2-cyclohexanediamine-N,N′-bis-(3-carboxylsalicylide), copper chloride and zinc chloride or manganese chloride under solvothermal conditions. They were characterized by various techniques including single-crystal X-ray diffraction, powder X-ray diffraction (XPRD), elemental analysis, TG analysis, IR and UV-visible spectroscopy. Compounds 1 and 2 are isostructural, and display an interesting windmill-type structure built from a trinuclear mixed-metal center [CuM2(CO2)6(H2O)2] (M = Mn 1, Zn 2) linked with six [CuLCl] (L = C14H16N2O3) units. The oxidation of cyclohexene catalysed by 1 and 2 as heterogeneous catalysts was investigated and showed high activity. In addition, a magnetic study indicates that antiferromagnetic interactions exist in compound 1.

Catalytic behavior of 1-(2-pyridylazo)-2-naphthol transition metal complexes encapsulated in y zeolite

The goal of this study is the preparation of new heterogeneous catalysts to be used in the oxidation of organic molecules under mild conditions. The metals in zeolite (M-Y) were prepared by the ion exchange method. The in situ encapsulation of selected transition metal complexes as a guest, namely cobalt(II), nickel(II), copper(II), and zinc(II), with 1-(2-pyridylazo)-2- naphthol (PAN) ligand in supercages of Y zeolite (host) was accomplished by the flexible ligand method. The coordination geometry of neat and Y-encapsulated metal complexes has been determined by molecular simulations. The resulting catalysts were fully characterized by different techniques (FTIR, SEM, and chemical analysis), and the results indicated that complexes were encapsulated in supercages of Y zeolite. Catalytic studies were performed in liquid phase for cyclohexene and cyclohexanol oxidations, by using tert-butylhydroperoxide as the oxidizing agent at 40 and 60 °C, respectively. All prepared catalysts exhibited catalytic activity for the oxidation reactions.

Lanthanide metal-organic frameworks for catalytic oxidation of olefins

Two isostructural lanthanide metal-organic frameworks (Ln-MOF-589, Ln = La3+, Ce3+), constructed from a tetratopic linker, benzoimidephenanthroline tetracarboxylic acid (H4BIPA-TC), have been solvothermally synthesized and characterized. These Ln-MOF-589 materials consist of Lewis acid [Ln2(-COO)6(-COOH)2(H2O)6] units and a naphthalene diimide core, which exhibited promising catalytic activity for the oxidation of olefins. Among them, Ce-MOF-589 exhibited outstanding performance with high conversions of styrene and cyclohexene (94 and 90%, respectively), and good selectivities towards styrene oxide and 2-cyclohexen-1-one (85, and 95%, respectively). Notably, the catalytic activity of Ce-MOF-589 outperformed that of homogeneous and heterogeneous catalysts, and representative MOFs. Also, Ce-MOF-589 can be recycled for at least up to six cycles with no significant loss of catalytic performance.

Allylic oxidation of olefins with a manganese-based metal-organic framework

Selective oxidation of olefins to α,β-unsaturated ketones under mild reaction conditions has attracted considerable interest, since α,β-unsaturated ketones can serve as synthetic precursors for various downstream chemical products. The major inherent challenges with this chemical oxidation are chemo- and regio-selectivity as well as environmental concerns, i.e. catalyst recycle, safety and cost. Using atmospheric oxygen as an environmentally friendly oxidant, we found that a metal-organic framework (MOF) constructed with Mn and a tetrazolate ligand (CPF-5) showed good activity and selectivity for the allylic oxidation of olefins to α,β-unsaturated ketones. Under the optimized conditions, we could achieve 98% conversion of cyclohexene and 87% selectivity toward cyclohexanone. The combination of a substoichiometric amount of TBHP (tert-butylhydroperoxide) and oxygen not only provides a cost effective oxidation system but significantly enhances the selectivity to α,β-unsaturated ketones, outperforming most reported oxidation methods. This catalytic system is heterogeneous in nature, and CPF-5 could be reused at least five times without a significant decrease in its catalytic activity and selectivity.

A highly efficient heterogeneous catalyst of cobalt-based coordination polymers for aerobic epoxidation of cyclohexene

A novel heterogeneous catalyst of cobalt-based coordination polymers has been successfully fabricated using a tyrosine-based derivative. Heterogeneous catalytic experiments on allylic oxidation of cyclohexene indicate that the titled complexes present high catalytic activities using tert-butyl hydroperoxide (t-BuOOH) as an oxidant. The activation energy for the whole process of oxidation of cyclohexene has been calculated to be 25.5 kJ mol-1, which indicates the important role of the selected ancillary ligands in the synthesis of the heterogeneous catalyst.

Cobalt(II) complexes with N,N,N-scorpionates and bidentate ligands: Comparison of hydrotris(3,5-dimethylpyrazol-1-yl)borate Tp? vs. Phenyltris(4,4-dimethyloxazolin-2-yl)borate ToM to control the structural properties and reactivities of cobalt centers

Scorpionate ligands Tp? (hydrotris(3,5-dimethylpyrazol-1-yl)borate) and ToM (tris(4,4- dimethyloxazolin-2-yl)phenylborate) complexes of cobalt(II) with bidentate ligands were synthesized. Both Tp? and ToM coordinate to cobalt(II) in a tridentate fashion when the bidentate ligand is the less hindered acetylacetonate. In crystal structures, the geometry of cobalt(II) supported by the N3O2 donor set in the Tp? complex is a square-pyramid, whereas that in the ToM complex is close to a trigonal-bipyramid. Both Tp?- and ToM-acac complexes exhibit solvatochromic behavior, although the changing structural equilibria of these complexes in MeCN are quite different. In the bis(1-methylimidazol-2-yl)methylphenylborate (LPh) complexes, Tp? retains the tridentate (k3) mode, whereas ToM functions as the bidentate (k2) ligand, giving the tetrahedral cobalt(II) complex. The bowl-shaped cavity derived from the six methyl groups on ToM lead to susceptibility to the bulkiness of the opposite bidentate ligand. The entitled scorpionate compounds mediate hydrocarbon oxidation with organic peroxides. Allylic oxidation of cyclohexene occurs mainly on the reaction with tert-butyl hydroperoxide (TBHP), although the catalytic efficiency of the scorpionate ligand complexes is lower than that of Co(OAc)2 and Co(acac)2. On cyclohexane oxidation with meta-chloroperbenzoic acid (mCPBA), both ToM and Tp? complexes function as catalysts for hydroxylation. The higher electron-donating ToM complexes show faster initial reaction rates compared to the corresponding Tp? complexes.

Copper-Functionalized Metal–Organic Framework as Catalyst for Oxidant-Controlled Partial Oxidation of Cyclohexene

Microwave irradiation is exploited for the facile, one-step functionalization of Cu(acac)2 to –NH2 pendant groups of MIL-53(Al)-NH2, a metal–organic framework material, under mild reaction conditions and a short reaction time. PXRD, XPS, XAS, and EPR spectroscopy are used to investigate the structure and chemical nature of the copper species on the framework. The copper center exists in the +2 oxidation state with a square-planar geometry and NO3 coordination environment. The copper complex is anchored to the framework by imine bond formation. This copper-functionalized MIL-53(Al)-NH2 or MIL-53[Cu] is employed in the catalytic oxidation of olefins using molecular oxygen (O2) or tert-butyl hydroperoxide (TBHP) as the oxidant. The chemoselectivities of the oxidation products depend on the type of oxidant and substrate. When O2 is used as the oxidant and isobutyraldehyde as the co-oxidant in the oxidation of cyclohexene with MIL-53[Cu], cyclohexene oxide is the major product. However, when TBHP is employed as the oxidant, 2-cyclohexen-1-one is the major product. Furthermore, the catalyst can be reused at least three times without a significant loss in activity.

Microwave-assisted one-pot functionalization of metal-organic framework MIL-53(Al)-NH2 with copper(ii) complexes and its application in olefin oxidation

A simple, rapid, and efficient functionalization of the metal-organic framework MIL-53(Al)-NH2 with copper(ii) complexes by microwave irradiation is described. The one-pot post-synthetic modification was based on the Schiff base reaction between the aldehyde added and the primary aryl amino group in the organic linker of MIL-53(Al)-NH2, which afforded coordination sites for copper(ii). The effects of synthetic parameters such as solvent, reaction time, and reactant ratio were evaluated. The functionalized materials were structurally characterized and examined for potential applications in catalysis. The copper complex functionalized MIL-53(Al) was active towards the oxidation of olefins with tert-butyl hydroperoxide as an oxidant. The results showed that if the olefin possessed allylic hydrogens such as cyclohexene, allylic oxidation products were obtained, but epoxide was the major product obtained from terminal olefins without allylic hydrogens. The reaction mechanism based on density functional theory calculations provides some insights into the observed experimental results.

2D Co-based coordination polymer with a histidine derivative as an efficient heterogeneous catalyst for the oxidation of cyclohexene

The hydrothermal reaction of CoCl2 and 4-((1-carboxy-2-(1H-imidazol-4-yl)ethylamino)methyl)benzoic acid (H2L) generated a {Co2(H2O)}-based 2D coordination framework, {(Co(L)(H2O))2(H2O)}n (1). Heterogeneous catalytic experiments on the allylic oxidation of cyclohexene show that activated 1 exhibits high catalytic activity using tert-butylhydroperoxide (t-BuOOH) as the oxidant toward the formation of tert-butyl-2-cyclohexenyl-1-peroxide. The activation energy for the oxidation of cyclohexene with catalyst 1 was approximately calculated as 91.98 kJ mol-1. This work demonstrates that a degree of creativity in the coordinatively unsaturated metal sites in CPs could significantly enhance their heterogeneous catalytic activity and selectivity.

Synthesis, structure, catalytic and magnetic properties of a pyrazole based five coordinated di-nuclear cobalt(II) complex

The reaction of 4-methyl-2,6-bis(3,5-dimethyl-1H-pyrazol-1-yl)methyl)phenol and Co(NO3)2·6H2O in MeCN gives rise to [Co2(L)2(N3)2] (1), a dinuclear five coordinated complex of Co(II), in satisfactory yield. The complex has been characterized by C, H and N microanalyses, FT-IR and UV-Vis spectral measurements. A single crystal X-ray diffraction study of 1 reveals that each Co(II) atom is in a distorted square-pyramidal geometry. Electrochemical studies in CH3CN showed that the Co(II)-Co(III)/Co(III)-Co(III) redox couple appears to be quasi-reversible (E1/2 = 0.409 V), while the corresponding Co(II)-Co(III)/Co(II)-Co(II) couple is mostly irreversible (E1/2 = -0.447 V). This complex displays modest catalytic activity toward the oxidation of various allylic compounds using TBHP as an oxidant in MeCN under mild conditions. A radical trapped experiment carried out in the presence of 4-tert-butylphenol clearly reveals that the epoxidation reactions occur purely through a radical pathway rather than a concerted one. Low temperature magnetic studies showed that the present Co(II) dimeric complex possesses a high positive magnetic anisotropy (D = +29.8 cm-1) and a weak ferromagnetic exchange interaction (2J = +10.3 cm-1).