128-38-1

Upstream product

• 2455-14-3 3,5,3',5'-tetra-tert-butyl-4,4'-diphenoquinone 
• 24457-07-6 3,3’,5,5’-tetra-tert-butyl-[1,1’-bis(cyclohexane)]-2,2’,5,5’-tetraene-4,4’-dione 
• 6386-58-9 4,4'-dithiobis(2,6-di-tert-butylphenol) 
• 110-86-1 pyridine 
• 955-02-2 2,6-di-tert-butyl-4-diazo-2,5-cyclohexadien-1-one 
• 507-19-7 t-butyl bromide 
• 92-88-6 4,4'-Dihydroxybiphenyl 
• 6975-85-5 1-methoxybutan-3-one 
• 128-39-2 2,6-di-tert-butylphenol 
• 3852-09-3 methyl 3-methoxypropionate 
• 5621-44-3 dimethyl 2-methylenepentanedioate 
• 110-82-7 cyclohexane 
• 2607-52-5 2,6-di-tert-butyl-4-methylene-2,5-cyclohexadien-1-one 
• 2179-51-3 4-(2,6-di-tert-butyl-4-methylphenoxy)-2,6-di-tert-butyl-4-methyl-2,5-cyclohexadien-1-one 

Downstream Products

• 2455-14-3 3,5,3',5'-tetra-tert-butyl-4,4'-diphenoquinone 
• 92-88-6 4,4'-Dihydroxybiphenyl 
• 98-51-1 4-tert-butyltoluene 
• 181648-66-8 2,6-Di-tert-butyl-4,4-bis-(3,5-di-tert-butyl-4-hydroxy-phenyl)-cyclohexa-2,5-dienone 
• 115-11-7 isobutene 
• 719-22-2 2,6-Di-tert-butyl-1,4-benzoquinone 

Relevant academic research and scientific papers

Magnetic Field Effects on the Catalytic Oxidation of 2,6-Di-tert-butylphenol by CoSMDPT: 2H and 17O Magnetic Isotope Effects

The effect of a magnetic field between 0 and 70 kG on the catalytic oxidation rate of 2,6-di-tert-butylphenol, DTBP, to form 2,6-di-tert-butylquinone, BQ, by cobalt(II) bis(3-(salicylideneamino)propyl)methylamine, CoSMDPT, in the presence of O2 is reported.No kinetic 2H isotope effect is observed with DTBP-OD, and DTBP-4-d1-OD exhibits mass and magnetic kinetic isotope effects of 1.25 and 1.22, respectively.In the presence of additive phenol, CoSMDPT catalyzes the formation of 2,2',6,6'-tetra-tert-butyldiphenoquinone, DPQ.The mass and magnetic isotope effects in DPQ formation are negligible for the deuteration of the phenolic position.DTBP-4-d1-OD in the presence of phenol-OD exhibits kinetic mass and magnetic 2H isotope effects in DPQ formation of 1.73 and 1.31, respectively.These results are compared to the oxidation rate of DTBP by Pb(OAc)4, which is unaffected by a 0-70-kG magnetic field and has a 2H kinetic isotope effect of 1.28 for DTBP-4-d1-OD.A significant 17O magnetic isotope effect is observed only for BQ production.The 17O enrichment of BQ given has an overall enrichment factor, S(f)=1.76, at 9percent DTBP conversion.These results are discussed in terms of a proposed mechanism.

Structure, Spectroscopy, and Reactivity of a Mononuclear Copper Hydroxide Complex in Three Molecular Oxidation States

Structural, spectroscopic, and reactivity studies are presented for an electron transfer series of copper hydroxide complexes supported by a tridentate redox-active ligand. Single crystal X-ray crystallography shows that the mononuclear [CuOH]1+ core is stabilized via intramolecular H-bonds between the H-donors of the ligand and the hydroxide anion when the ligand is in its trianionic form. This complex undergoes two reversible oxidation processes that produce two metastable "high-valent"CuOH species, which can be generated by addition of stoichiometric amounts of 1e- oxidants. These CuOH species are characterized by an array of spectroscopic techniques including UV-vis absorption, electron paramagnetic resonance (EPR), and X-ray absorption spectroscopies (XAS), which together indicate that all redox couples are ligand-localized. The reactivity of the complexes in their higher oxidation states toward substrates with modest O-H bond dissociation energies (e.g., 4-substitued-2,6-di-tert-butylphenols) indicates that these complexes act as 2H+/2e- oxidants, differing from the 1H+/1e- reactivity of well-studied [CuOH]2+ systems.

Novel photochemical coupling of hindered phenols in the presence of acridine mechanistically probed by CIDEP

Irradiation of hindered phenols in the presence of acridine as a light absorber gives bisphenols and biacridane.CIDEP study establishes the path of hydrogen abstraction by the triplet acridine.The overall mechanism is proposed by the product analysis and the CIDEP studies.

Performance of 4,4'-Bis(2,6-di-tert-butylphenol) in stabilization of isoprene rubber and polypropylene

The antioxidant performance of a sterically hindered bisphenol antioxidant, 4,4'-bis(2,6-di-tert-butylphenol), in model reactions of accelerated aging of carbon-chain polymers (polypropylene, isoprene rubber) was studied. This antioxidant was examined by differential scanning calorimetry and Wallace plasticity measurements in comparison with known commercial phenolic and amine stabilizers. High performance of 4,4'-bis(2,6-di-tert-butylphenol) as antioxidant was revealed.

Liquid-phase oxidation of 2,6-di-tert-butylphenol with Cu-impregnated MCM-41 catalysts in the presence of alkali metals

Mesoporous silicate MCM-41, with a uniform pore diameter of ca. 35 A, was used as a support for impregnated Cu catalysts for liquid-phase oxidation of 2,6-di-tert-butylphenol (BOH) in the presence of a base such as KOH. The oxidation products were 4,4′-dihydroxy-3,3′,5,5′-tetra-tert-butyl-biphenyl (H2DPQ) and 3,3′,5,5′-tetra-tert-butyl-4,4′-diphenoquinone (DPQ). An alkali such as a potassium salt, which promotes the phenol oxidation activity of copper ion-impregnated MCM-41 (Cu/MCM-41) catalyst, was found to be more effective as an additive to the reaction solution than impregnation on the Cu/MCM-41 catalyst. The added alkali was found to play a role in generating the corresponding phenolate anion by dissolving a BOH molecule. H2DPQ is formed through tautomerization of an intermediate dimer obtained by the C-C coupling of the corresponding phenoxy radicals. DPQ is formed via the consecutive oxidation of H2DPQ and/or via the oxidative dehydrogenation of the intermediate dimer. The BOH molecules in the mesopores of Cu/MCM-41, rather than the BOH in bulk solution in the presence of CuCl2, were found to favor H2DPQ production. Cu/MCM-41 with added potassium [(K-Cu)/MCM-41] was much more active for phenol oxidation than Cu-impregnated NaZSM-5 with added potassium [(K-Cu)/NaZSM-5] or the corresponding NaY [(K-Cu)/NaY], each catalyst having only uniform micropores. This result indicates that the oxidation of sterically bulky BOH occurs mainly at the active sites in the mesopores and is difficult to carry out in the micropores of (K-Cu)/NaZSM-5 and (K-Cu)/NaY zeolites because of the steric bulkiness of the oxidation products, H2DPQ and DPQ. The liquid-phase adsorption amounts of BOH on NaZSM-5 and NaY were found to be comparable to that on MCM-41. The shape selectivity by the oxidation products in the micropores of (K-Cu)/NaZSM-5 and (K-Cu)/NaY zeolites was thus suggested to inhibit the BOH oxidation activities of both catalysts, based on the results of the oxidation reaction and liquid-phase adsorption of BOH.

Electrooxidative Coupling of Phenols. I. Product-Selective Electrosynthesis of 2,2',6,6'-Tetra-tert-butyl-1,1'-biphenol from 2,6-Di-tert-butylphenol

Biphenol electrosynthesis is achieved in a divided cell by a set of redox reactions from 2,6-di-tert-butylphenol (4) via the corresponding diphenoquinone 3.Phenol 4 can also lead to either the corresponding biphenol 2 or diphenoquinone 3 in a product-selective manner by electrooxidation in an undivided cell.The choice of solvent is a crucial factor for the product-selectivity.

Antibacterial activity of dipropofol and related compounds

Phenolic compounds, in general, exhibit antioxidant and antibacterial activities. We studied antimicrobial activity of the phenolic antioxidants, propofol (2,6-diisopropylphenol), tocopherol, eugenol, butylated hydroxyanisole (BHA), and several of their dimer compounds. Dipropofol (dimer of 2,6-diisopropylphenol) showed strong antibacterial activity against gram-positive strains including methicillin resistant Staphylococcus aureus (MRSA) and vancomycin resistant Enterococci (VRE), while propofol and other monomeric and dimeric phenols having methyl or tert-butyl groups showed no remarkable activity. The results indicated that the dimeric structure of 2,6-diisopropylphenol moiety may play an important role in the antibacterial activity.

Reduction of 4,4′-stilbenequinone and 4,4′-diphenoquinone upon reaction with photogenerated radicals

The properties of 3,3′,5,5′-tetra-tert-butyl-4,4′- stilbenequinone (StQ) were studied by photochemical means. Acetone, acetophenone or benzophenone was photolyzed in the presence of both StQ and a donor, such as alcohols or triethylamine. This initiated reaction of a ketyl radical with StQ to form a semiquinone radical and eventually induce a permanent bleaching due to conversion of StQ to 4,4′-dihydroxystilbene (StQH2). The quantum yield of conversion of StQ to StQH2 increases with the donor concentration. Similar effects were found for the ketone-sensitized radical-induced conversions of the analogous diphenoquinone to the reduction product, diphenol.

(Nitrosonaphtholato)metal complex-catalyzed oxidation of phenols and alkenes

Bis(1-nitroso-2-naphtholato)manganese(II), tris(1-nitroso-2-naphtholato)manganese(III), tris(2-nitroso-1-naphtholato)manganese(III), bis(1-nitroso-2-naphtholato)cobalt(II), bis(1-nitroso-2-naphtholato)nickel(II), bis(1-nitroso-2-naphtholato)copper(II) and bis(1-nitroso-2-naphtholato)zinc(II) were prepared and their catalytic abilities in the oxidation of phenols were examined. The best yields of diphenoquinones were obtained when the catalytic oxidation using bis(1-nitroso-2-naphtholato)manganese(II) was carried out at 23°C under an oxygen atmosphere (1 atm) in the presence of a phosphine ligand. Likewise, phenols were completely converted to the corresponding diphenoquinones together with small amounts of benzoquinones under an oxygen pressure (20 atm) at 50°C in a short period of time. It was proven that the manganese(II) catalyst, molecular oxygen, and phosphine ligand were essential for the catalytic phenol oxidation. On the other hand. bis(1-nitroso-2-naphtholato)manganese(II)-catalyzed epoxidation of alkenes was only effective when iodosylbenzene was used. The catalytic oxidation mechanism was discussed on the basis of the measurement of cyclic voltammograms of the (nitrosonaphtholato)metal complexes, isolated intermediates, and effect of additives.

Clean synthesis of 3,3′,5,5′-Tetra-tert-butyl-4,4′-diphenoquinone from the oxidative coupling of 2,6-Di-tert-butylphenol catalyzed by alkali-promoted Cu-Mg-Al hydrotalcites in the presence of molecular oxygen

2,6-Di-tert-butylphenol is selectively transformed to 3,3′,5,5′-tetra-tert-butyl-4,4′-diphenoquinone in the presence of molecular oxygen using alkali-promoted Cu-Mg-Al hydrotalcites as recyclable heterogeneous catalysts.