- Purification method of 3, 3 ', 5, 5'-tetrasubstituent-2, 2 '-biphenol
-
The invention relates to the technical field of organic chemical industry, in particular to a purification method of 3, 3 ', 5, 5'-tetrasubstituent-2, 2 '-biphenol, which comprises the following steps: A) stirring and mixing 3, 3', 5, 5 '-tetrasubstituent-2, 2'-biphenol and a purifying agent to obtain a mixed material; wherein the purifying agent comprises one or more of liquid organic alcohol compounds; and B) carrying out solid-liquid separation on the mixed material, and drying the obtained solid product to obtain the purified 3, 3 ', 5, 5'-tetrasubstituent-2, 2 '-biphenol. The purification of 3, 3 ', 5, 5'-tetrasubstituent-2, 2 '-biphenol is realized under specific process steps by adopting the purifying agent with specific composition, and the method is simple in process, mild in condition, recyclable in purifying agent, low in material consumption and energy consumption, high in overall operability, capable of effectively improving the purity and appearance of the product and high in yield of the purified product.
- -
-
Paragraph 0085-0092; 0109-0122
(2021/06/23)
-
- Hypoiodite-catalysed oxidative homocoupling of arenols and tandem oxidation/cross-coupling of hydroquinones with arenes
-
We report the hypoiodite-catalyzed oxidative C-C homocoupling of arenols to biarenols or biquinones using aqueous hydrogen peroxide as an oxidant. In addition, by combining hypoiodite catalysis and lipophilic Lewis acid-assisted Br?nsted acid catalysis under aqueous conditions, we achieved a tandem oxidation/cross-coupling reaction of hydroquinones with electron-rich arenes. These results highlight the substantial scope of hypoiodite/acid co-catalysis for use in oxidative coupling reactions.
- Uyanik, Muhammet,Nagata, Dai,Ishihara, Kazuaki
-
supporting information
p. 11625 - 11628
(2021/11/12)
-
- Counterion-Enhanced Pd/Enamine Catalysis: Direct Asymmetric α-Allylation of Aldehydes with Allylic Alcohols by Chiral Amines and Achiral or Racemic Phosphoric Acids
-
We report a straightforward and efficient Pd/enamine catalytic procedure for the direct asymmetric α-allylation of branched aldehydes. The use of simple chiral amines and easily prepared achiral or racemic phosphoric acids, together with a suitable Pd-source resulted in a highly active and enantioselective catalyst system for the allylation of various α-branched aldehydes with different allylic alcohols. The reported procedure could provide an easy access to both product antipodes. Furthermore, two possible orthogonal derivatizations of the enantioenriched aldehydes were performed without any decrease in enantioselectivity.
- Pálv?lgyi, ádám Márk,Smith, Jakob,Schnürch, Michael,Bica-Schr?der, Katharina
-
p. 850 - 860
(2021/01/09)
-
- High iso Aldehyde Selectivity in the Hydroformylation of Short-Chain Alkenes
-
The hydroformylation of propene to give predominantly iso-butanal has been achieved; class-leading selectivity is possible even at higher temperatures that deliver fast conversion. Racemic rhodium complexes of bidentate phospholane phosphites derived from tropos-biphenols and unusual solvent systems are the key to the selectivity observed.
- Iu, Leo,Fuentes, José A.,Janka, Mesfin E.,Fontenot, Kevin J.,Clarke, Matthew L.
-
supporting information
p. 2120 - 2124
(2019/01/25)
-
- Highly isoselective catalyst for alkene hydroformylation
-
Ligands for use with catalyst compositions used in hydroformylation reactions are described herein. The ligands are used with various ester solvents and achieve an increase in isoselectivity with an increase in temperature, an increase in TON with an increase in temperature, and/or will show isoselectivity that is surprisingly high in comparison to the hydroformylation reactions using common solvents.
- -
-
Page/Page column 12; 14
(2019/02/07)
-
- Highly isoselective catalyst for alkene hydroformylation
-
Ligands for use with catalyst compositions used in hydroformylation reactions are described herein. The ligands are used with various octofluorotoluene or hydrocarbon solvents and achieve an increase in isoselectivity with an increase in temperature, an increase in TON with an increase in temperature, and/or will show isoselectivity that is surprisingly high in comparison to the hydroformylation reactions using common solvents.
- -
-
Page/Page column 15
(2019/01/04)
-
- Designing highly efficient Rh/CPOL-bp&PPh3 heterogenous catalysts for hydroformylation of internal and terminal olefins
-
Vinyl functionalized Biphephos ligand, denoted as vinyl biphephos, has been succesfully synthesized. Copolymerization of vinyl biphephos with tris(4-vinphenyl) phosphane can afford an efficient Porous Organic Polymer (POP), CPOL-bp&PPh3. The ultimately formed Rh/CPOL-bp&PPh3 heterogeneous catalyst showed excellent performance in converting terminal olefins to the corresponding linear aldehydes with high regioselectivity (l/b = 96:4-98:2), activity and stability, even better than the comparable homogeneous Rh + vinyl biphephos system. Notably, isomerizing hydrofromylation of internal olefins (2-heptene, 2-octene, trans-3-hexene) was also performed with high regioselectivity (l/b = 92:8-93:7) using the Rh/CPOL-bp&PPh3 heterogeneous catalyst.
- Li, Cunyao,Xiong, Kai,Yan, Li,Jiang, Miao,Song, Xiangen,Wang, Tao,Chen, Xingkun,Zhan, Zhuangping,Ding, Yunjie
-
p. 2143 - 2149
(2016/04/26)
-
- PROCESS FOR PREPARING 2,2'-DIHYDROXY-3,3'-DI-TERT-BUTYL-5,5'-DIMETHOXY-1,1'-BIPHENOL
-
Process for preparing 2,2′-dihydroxy-3,3′-di-tert-butyl-5,5′-dimethoxy-1,1′-biphenol.
- -
-
Paragraph 0033; 0034
(2016/12/16)
-
- Hydrolysis stability of bidentate phosphites utilized as modifying ligands in the Rh-catalyzed n-regioselective hydroformylation of olefins
-
The stability of ligands and catalysts is an almost neglected issue in homogeneous catalysis, but it is crucial for successful application of this methodology in technical scale. We have studied the effect of water on phosphites, which are the most applied cocatalysts in the n-regioselective homogeneous Rh-catalyzed hydroformylation of olefins. The stability of the bidentate nonsymmetrical diphosphite L1, as well as its two monophosphite constituents L2 and L3, toward hydrolysis was investigated by means of in situ NMR spectroscopy under similar conditions as applied in industry. Hydrolysis pathways, intermediates, and kinetics were clarified. DFT calculations were used to support the experimentally found data. The acylphosphite unit L2, which reacts with water in an unselective manner, was proven to be much less stable than the phenolphosphite L3. The stability of the bidentate ligand L1 can be therefore mainly attributed to its phenolphosphite moiety. With an excess of water, the hydrolysis of L1 and L2 as well as their Rh-complexes is first-order with respect to the phosphite. Surprisingly, coordination to Rh significantly stabilizes the monodentate ligand L2, while in strong contrast, the bidentate ligand L1 decomposes faster in the Rh complex. NMR spectroscopy provided evidence for the existence of species from decomposition of phosphites, which can likewise coordinate as ligands to the metal. Electron-withdrawing groups in the periphery of the acylphosphite moiety decrease the stability of L1, whereas 3,5-disubstituted salicylic acid derivatives with bulky groups showed superior stability. These modifications of L1 also give rise to different catalytic performances in the n-regioselective hydroformylation of n-octenes and 2-pentene, from which the 3,5-di-t-butyl-substituted ligand offered a higher n-regioselectivity accompanied by a lowering of the reaction rate in comparison to the parent ligand L1.
- Zhang, Baoxin,Jiao, Haijun,Michalik, Dirk,Klo?, Svenja,Deter, Lisa Marie,Selent, Detlef,Spannenberg, Anke,Franke, Robert,B?rner, Armin
-
p. 7554 - 7565
(2018/05/23)
-
- Cobalt(II)-porphyrin-catalyzed aerobic oxidation: Oxidative coupling of phenols
-
The first example of the cobalt-porphyrin-catalyzed aerobic oxidative coupling of phenols through oxidative C-H functionalization has been developed. In the presence of T(p-OMe)PPCo and Na2CO3, the oxidative coupling of phenols with different substituents proceeded smoothly with O 2 as a terminal oxidant to give the corresponding biaryl compounds in satisfactory yields. The biaryl derivatives are important in the area of pharmaceuticals and as ligands in metal catalysis. Preliminary mechanistic studies of this oxidative coupling reaction are also reported. The T(p-OMe)PPCo-catalyzed oxidative coupling of phenols was developed for the synthesis of biphenols. This reaction features low catalyst loadings, mild reaction conditions, and operational simplicity. Preliminary mechanistic studies were conducted.
- Jiang, Qing,Sheng, Wenbing,Tian, Mi,Tang, Jie,Guo, Cancheng
-
supporting information
p. 1861 - 1866
(2013/04/24)
-
- A homogeneous, recyclable polymer support for rh(I)-catalyzed c-c bond formation
-
A robust and practical polymer-supported, homogeneous, recyclable biphephos rhodium(I) catalyst has been developed for C-C bond formation reactions. Control of polymer molecular weight allowed tuning of the polymer solubility such that the polymer-supported catalyst is soluble in nonpolar solvents and insoluble in polar solvents. Using the supported rhodium catalysts, addition of aryl and vinylboronic acids to the electrophiles such as enones, aldehydes, N-sulfonyl aldimines, and alkynes occurs smoothly to provide products in high yields. Additions of terminal alkynes to enones and industrially relevant hydroformylation reactions have also been successfully carried out. Studies show that the leaching of Rh from the polymer support is low and catalyst recycle can be achieved by simple precipitation and filtration.
- Jana, Ranjan,Tunge, Jon A.
-
experimental part
p. 8376 - 8385
(2011/12/04)
-
- A homogeneous, recyclable rhodium(l) catalyst for the hydroarylation of michael acceptors
-
A robust and practical polymer-supported, recyclable biphephos rhodium(l) catalyst has been developed. Control of polymer molecular weight allowed the tuning of solubility such that the polymer-supported catalyst is soluble in nonpolar solvents and not soluble in polar solvents. Thus, catalytic addition of aryl- and vinylboronic acids to enones occurs under completely homogeneous conditions and catalyst recycle can be achieved by simple precipitation and filtration.
- Jana, Ranjan,Tunge, Jon A.
-
supporting information; experimental part
p. 971 - 974
(2009/07/11)
-
- One-pot synthesis of dibenzofuran-1,4-diones
-
One-pot synthesis of dibenzofuran- 1,4-diones 8 from 4-methoxyphenols (or 4-methoxy-1-naphthols) 4 was achieved by oxidative dimerization over a semiconductor in heated, O2-saturated toluene, followed by selective monodemethylation, and oxidati
- Takeya, Tetsuya,Kondo, Hiromu,Tomita, Kazuho,Okamoto, Iwao,Morita, Nobuyoshi,Tamura, Osamu
-
p. 961 - 968
(2008/09/19)
-
- Novel template-directed anodic phenol-coupling reaction
-
Substituted phenols were anodically coupled to the corresponding 2,2'-biphenols via tetraphenoxy borate derivatives. This electrochemical method is particularly useful for methyl-substituted substrates, such as 2,4-dimethyl phenol. The selective ortho-coupling reaction can be easily performed on a multikilogram scale.
- Malkowsky, Itamar M.,Rommel, Christina E.,Froehlich, Roland,Griesbach, Ulrich,Puetter, Hermann,Waldvogel, Siegfried R.
-
p. 7482 - 7488
(2007/10/03)
-
- Antioxidant activity of propofol and related monomeric and dimeric compounds
-
This study was carried out to investigate the antioxidant activity of propofol (2,6-diisopropylphenol) and its related compounds, butylated hydroxyanisole (BHA), 2,6-dimethylphenol, 2,6-di-t-butylphenol, and their dimeric compounds. The degree of antioxidant activity was evaluated based on the degree of peroxidation induced with Fe-ascorbic acid in egg phosphatidylcholine through the determination of thiobarbituric acid-reactive substances (TBARS) formed during peroxidation. Their antioxidant activities were in the order of dipropofol>di(2,6-di-t-butylphenol)>diBHA>di(2,6-dimethylphenol). Dipropofol, a dimeric compound of propofol, showed the highest antioxidant activities. Dimeric compounds had higher activities than monomeric compounds, and the 1,1-diphenyl-p-picryhydrazyl-trapping ability of dimeric compounds was also greater than those of monomeric compounds (4-10-fold). These results suggest that dimeric phenols may increase their antioxidant activities along with increments in the conjugation system and play a inhibitory role in the propagation of free radical chain reactions.
- Ogata, Masahiro,Shin-Ya, Kazuo,Urano, Shiro,Endo, Toyoshige
-
p. 344 - 346
(2007/10/03)
-
- 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.
- Ogata, Masahiro,Sato, Kanae Tutumimoto,Kunikane, Takao,Oka, Kentaro,Seki, Masako,Urano, Shiro,Hiramatsu, Keiichi,Endo, Toyoshige
-
p. 1120 - 1122
(2007/10/03)
-
- Sterically demanding diphosphonite ligands - Synthesis and application in nickel-catalyzed isomerization of 2-methyl-3-butenenitrile
-
The synthesis of a novel class of sterically demanding diphosphonites 1-8, based on rigid backbones, is described. The starting materials are all commercially available and the methodology allows for a modular approach. All ligands have been fully characterized, including an X-ray crystal structure for compound 1, 4,5-bis{di[(2-terr-butyl)phenyl]phosphonito}-9,9-dimethylxanthene. The coordination of these diphosphonite ligands towards Ni(II) and Ni(0) precursors is investigated, both by NMR spectroscopy as well as X-ray crystallography and compared with the behaviour of diphosphine ligands such as Xantphos. The molecular structure for complex 9, trans-[NiBr2(1)] is described in detail. The nickel-catalyzed isomerization of 2-methyl-3- butenenitrile to 3-pentenenitrile is studied, a relevant step in the industrially important hydrocyanation of butadiene (the DuPont adiponitrile process). Good activities and selectivities to the desired 3-pentenenitrile are obtained in this reversible C-C bond activation reaction.
- Van Der Vlugt, Jarl Ivar,Hewat, Alison C.,Neto, Samuel,Sablong, Rafael,Mills, Allison M.,Lutz, Martin,Spek, Anthony L.,Mueller, Christian,Vogt, Dieter
-
p. 993 - 1003
(2007/10/03)
-
- Method for hydroformylation, xanthene-bridged ligands and catalyst comprising a complex of said ligands
-
In a process for the hydroformylation of ethylenically unsaturated compounds, at least one complex of a metal of transition group VIII. with at least one phosphorus-, arsenic- or antimony-containing compound as ligand is used as hydroformylation catalyst, where the compound used as ligand in each case comprises two groups which comprise a P, As or Sb atom and at least two further hetero atoms and are bound to a xanthene-like molecular framework. New compounds of this type and catalysts which comprise at least one complex of a metal of transition group VIII. with at least one such compound as ligand are also provided.
- -
-
Page/Page column 11
(2008/06/13)
-
- Antioxidant Synergism Between Butylated Hydroxyanisole and Butylated Hydroxytoluene
-
Decay of the 2,6-di-tert-butyl-4-methylphenoxy radical in the presence of butylated hydroxyanisole (BHA) was investigated in 1,2-dimethoxyethane with or without triethylamine.BHT-radical was conveniently generated by dissociation of its unstable dimer in solution.The products were BHT, 3,3'-di-tert-butyl-5,5'-dimethoxy-2,2'-dihydroxybiphenyl (BHA-dimer), 2,6-di-tert-butyl-p-quinone methide (QM), 1,2-bis(3,5-di-tert-butyl-4-hydroxyphenyl)ethane, and 3,3',5,5'-tetra-tert-butyl-4,4'-stilbenequinone.The reaction without added triethylamine gave larger quantities of the last two products and BHA (recovery), whereas the reaction with it provided larger quantities of the first two products.The marked difference in the product distribution can be accounted for by a series of reactions including reversible dehydrogenation of BHA with BHT-radical, which generates 2-tert-butyl-4-methoxyphenoxy radical (BHA-radical) and BHT, reversible dimerization of BHA-radical, which affords an intermediary bis(cyclohexadienone), and spontaneous and base-catalysed prototropic rearrangement of the intermediate into BHA-dimer.Products of coupling between BHT-radical and BHA-radical were not obtained.BHA was found to undergo facile acid-catalyzed addition to QM, providing two isomeric bis(hydroxyphenyl)methanes.The results help to elucidate the mechanism of antioxidant synergism between BHA and BHT and may suggest that the synergism can be affected by base or acid. - Key words: Antioxidant synergism; butylated hydroxyanisole; butylated hydroxytoluene; effect of acid; effect of base; fate of phenoxy radicals involved.
- Omura, Kanji
-
p. 1565 - 1570
(2007/10/03)
-
- Mechanism of the Gibbs Reaction. 3. Indophenol Formation via Radical Electrophilic Aromatic Substitution (SREAr) on Phenols
-
Different products are formed, depending on the para substituent (R) when 2,6-dichlorobenzoquinone N-chloroimine (1b) reacts with the anion of the 4-substituted phenol (2).If the group R can leave as a cation (i.e., R is an electrofugal leaving group) such as H, CH2NMe2, CH2OH, etc., then the reaction yields indophenol (3), the normal Gibbs product.If the group R cannot leave as a cation such as CH3, the final product of the reaction will be type 10, 1,1-disubstituted 2,5-cyclohexadienone.If the group R is OH or NH2, then the reaction gives the corresponding benzoquinone 4 or benzoquinone imine 1 and 2,6-dichlorobenzoquinone imine (1d).In all these cases the reaction proceeds at a 1:1 stoichiometry.If, however, the group R can leave as an anion (i.e., R is a nucleofugal leaving group) such as halogen, alkoxy, or OCH2Ph, then the reaction proceeds at a 1:2 stoichiometry.In this case the reaction of a second mole of phenolate with type 26 intermediate yields the indophenol product 3 and the oxidized product of the phenol.If the two ortho positions of the phenolate are substituted then the oxidized product of the phenol will be the corresponding benzoquinone.The mechanism of the reaction has been studied by kinetic and nonkinetic (NMR) methods.It has been concluded that the first step of the mechanism is a single electron transfer (SET) from the phenolate to the benzoquinone N-chloroimine 1b which is the rate-determining process in most of the cases.In some of the nucleofugal cases the final oxidation, involving the second mole of phenolate, is the rate-determining step.For the radical reaction three different alternatives are suggested: a combination of radicals in a solvent cage (direct reaction) and two different chain reactions (chain A and chain B).Quantum chemical calculations revealed that the direct reaction and the chain A mechanisms were energetically more favored than chain B.The reaction shows an extremely large para selectivity although the substitution does follow a radical mechanism.
- Pallagi, Istvan,Toro, Andras,Farkas, Oedoen
-
p. 6543 - 6557
(2007/10/02)
-
- Oxidation by Singlet Oxygen of 4,7-Dimethoxy-2,9-di-t-butyloxepinobenzofuran, an Oxidation Product of the Antioxidant BHA
-
Tetraphenylporphin-sensitized photo-oxidation of 4,7-dimethoxy-2,9-di-t-buthyloxepinobenzofuran (3) and reaction of the products with methanol cleaves the oxepine ring, producing the acetal (9) and its isomer (13), which may be derived respectively from the 1,4-endoperoxide and 1,2-dioxetane oxygen adducts of (3).The geometrical isomerization of (9) to (14), and the acid-catalysed hydrolysis of (9), (13) and (14) to the dihydrofuranylidenebenzofuranone (18) are described.Crystal structures were determined for compounds (9), (14), and (18).
- Byrne, Lindsay T.,Engelhardt, Lutz M.,Hewgill, Frank R.,Skelton, Brian W.,White, Allan H.,Foote, Christopher S.
-
p. 133 - 142
(2007/10/02)
-
- Studies on the Antioxidants. XX. The Effect of Butylated Hydroxytoluene on tert-Butylhydroperoxide-Induced Oxidation of Butylated Hydroxyanisole
-
Hydrogen donation from butylated hydroxyanisole (BHA) and/or butylated hydroxytoluene (BHT) to the peroxyl radical prepared by cobalt-catalyzed cleavage of tert-butylhydroperoxide was investigated, and the relation of this process to synergism in the antioxidative effect was discussed.BHA initially donated a hydrogen to the peroxyl radical to form its phenoxyl radical to form its phenoxyl radical, and this radical reacted with either the peroxyl radical or another phenoxyl radical to form its adduct.In the combination of BHA and BHT, BHA donated a hydrogen to the peroxyl radical initially, and its phenoxyl radical accepted hydrogen from BHT to regenerate BHA, with enhanced oxidation of BHT to quinone methide.This hydrogen acceptance of the phenoxyl radical of BHA from BHT may be closely correlated with the synergism in the antioxidative effect of the mixture of BHA and BHT.
- Kurechi, Tsutao,Kato, Tetsuta
-
p. 1772 - 1776
(2007/10/02)
-