14078-41-2Relevant academic research and scientific papers
Purification method of 3, 3 ', 5, 5'-tetrasubstituent-2, 2 '-biphenol
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Paragraph 0085-0092; 0109-0122, (2021/06/23)
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.
Hypoiodite-catalysed oxidative homocoupling of arenols and tandem oxidation/cross-coupling of hydroquinones with arenes
Uyanik, Muhammet,Nagata, Dai,Ishihara, Kazuaki
supporting information, p. 11625 - 11628 (2021/11/12)
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.
Counterion-Enhanced Pd/Enamine Catalysis: Direct Asymmetric α-Allylation of Aldehydes with Allylic Alcohols by Chiral Amines and Achiral or Racemic Phosphoric Acids
Pálv?lgyi, ádám Márk,Smith, Jakob,Schnürch, Michael,Bica-Schr?der, Katharina
, p. 850 - 860 (2021/01/09)
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.
High iso Aldehyde Selectivity in the Hydroformylation of Short-Chain Alkenes
Iu, Leo,Fuentes, José A.,Janka, Mesfin E.,Fontenot, Kevin J.,Clarke, Matthew L.
supporting information, p. 2120 - 2124 (2019/01/25)
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.
Highly isoselective catalyst for alkene hydroformylation
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Page/Page column 12; 14, (2019/02/07)
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.
Highly isoselective catalyst for alkene hydroformylation
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Page/Page column 15, (2019/01/04)
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.
Hydrolysis stability of bidentate phosphites utilized as modifying ligands in the Rh-catalyzed n-regioselective hydroformylation of olefins
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)
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.
Designing highly efficient Rh/CPOL-bp&PPh3 heterogenous catalysts for hydroformylation of internal and terminal olefins
Li, Cunyao,Xiong, Kai,Yan, Li,Jiang, Miao,Song, Xiangen,Wang, Tao,Chen, Xingkun,Zhan, Zhuangping,Ding, Yunjie
, p. 2143 - 2149 (2016/04/26)
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.
PROCESS FOR PREPARING 2,2'-DIHYDROXY-3,3'-DI-TERT-BUTYL-5,5'-DIMETHOXY-1,1'-BIPHENOL
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Paragraph 0033; 0034, (2016/12/16)
Process for preparing 2,2′-dihydroxy-3,3′-di-tert-butyl-5,5′-dimethoxy-1,1′-biphenol.
Cobalt(II)-porphyrin-catalyzed aerobic oxidation: Oxidative coupling of phenols
Jiang, Qing,Sheng, Wenbing,Tian, Mi,Tang, Jie,Guo, Cancheng
supporting information, p. 1861 - 1866 (2013/04/24)
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.
