36433-51-9Relevant academic research and scientific papers
Cross-linked reverse micelles with embedded water pools: A novel catalytic system based on amphiphilic block copolymers
Liu, Ruihan,Wang, Shiping,Yao, Jia,Xu, Weiwei,Li, Haoran
, p. 38234 - 38240 (2014)
Based on the idea of structural design, a novel catalytic system was developed from a block copolymer for the oxidation reaction of 2,3,6-trimethylphenol (TMP). The block copolymer, poly(4-vinylpyridine)-block- poly(ethylene glycol)-block-poly(4-vinylpyridine) (P4VP-PEG-P4VP), was synthesized via anionic polymerization. After self-assembly in water-1-hexanol solution and shell cross linking, the block copolymer formed the shell cross-linked reverse micelles (SCRMs). The CuCl2 complexed SCRMs were used in the catalytic oxidation reaction of TMP. Through coordinating with metal ions, regulating the distribution of metal catalytic active centers, and with the cocatalysis effect of the immobilized water droplets, this polymer-supported catalyst system demonstrated an efficient catalytic activity and recoverability. This work not only provides a promising catalyst based on mesoscale structure design using block copolymers but is also an example for deeper understanding on the structure effect in catalysis. the Partner Organisations 2014.
Insight into 2,3,6-Trimethylphenol oxidation by comparing the difference between cupric acetate and cupric chloride catalysis
Wang, Guanqi,Wang, Yongtao,Yao, Jia,Li, Haoran
, p. 10 - 16 (2019)
The oxidation of 2,3,6-trimethylphenol with molecular oxygen produced 2,3,5-trimethyl-1,4-benzoquinone (TMBQ) by using CuCl2 as the catalyst, however, it led to coupling when the catalyst was replaced by Cu(OAc)2. To gain deeper insight into the difference of the catalytic mechanism, the in-depth studies were carried out by controlled experiments such as adding CuCl2 at different times into the system initially catalyzed by Cu(OAc)2 and by using the electron paramagnetic resonance (EPR). In controlled experiments, the oxygenation reaction is dominant when adding CuCl2. In EPR, the phenoxyl radical was detected in the Cu(OAc)2 catalysis system, but not found in the CuCl2 system. All these results suggested that the rate of oxygenation catalyzed by CuCl2 was much faster than that of coupling, which was reinforced by the kinetics experiments. The attacking of activated molecular oxygen by CuCl2 on the phenoxyl radical is proposed as the major route to obtain TMBQ. In the process, the interaction existed between Cl and H-atom at para-position to help eliminating proton by DFT calculation. Moreover, the CuCl2 was inactivated by multidentates ligands suggested the coordination sites on the catalyst should play key roles in oxygenation.
Aromatic substitution in ball mills: Formation of aryl chlorides and bromides using potassium peroxomonosulfate and NaX
Schmidt, Robert,Stolle, Achim,Ondruschka, Bernd
, p. 1673 - 1679 (2013/02/22)
Aryl chlorides and bromides are formed from arenes in a ball mill using KHSO5 and NaX (X = Cl, Br) as oxidant and halogen source, respectively. Investigation of the reaction parameters identified operating frequency, milling time, and the number of milling balls as the main influencing variables, as these determine the amount of energy provided to the reaction system. Assessment of liquid-assisted grinding conditions revealed, that the addition of solvents has no advantageous effect in this special case. Preferably activated arenes are halogenated, whereby bromination afforded higher product yields than chlorination. Most often reactions are regio- and chemoselective, since p-substitution was preferred and concurring side-chain oxidation of alkylated arenes by KHSO5 was not observed. The Royal Society of Chemistry.
Structure-activity relationships for inhibition of inosine monophosphate dehydrogenase by nuclear variants of mycophenolic acid
Nelson, Peter H.,Carr, Stephen F.,Devens, Bruce H.,Eugui, Elsie M.,Franco, Fidencio,Gonzalez, Carlos,Hawley, Ronald C.,Loughhead, David G.,Milan, David J.,Papp, Eva,Patterson, John W.,Rouhafza, Sussan,Sjogren, Eric B.,Smith, David B.,Stephenson, Rebecca A.,Talamas, Francisco X.,Waltos, Ann-Marie,Weikert, Robert J.,Wu, John C.
, p. 4181 - 4196 (2007/10/03)
Structure-activity relationships in the region of the phthalide ring of the inosine monophosphate dehydrogenase inhibitor mycophenolic acid have been explored. Replacement of the lactone ring with other cyclic moieties resulted in loss of potency, especia
Synthesis of Alkyl Substituted p-Benzoquinones from the Corresponding Phenols Using Molecular Oxygen Catalyzed by Copper(II) Chloride-Amine Hydrochloride Systems
Shimizu, Masao,Watanabe, Yoshihito,Orita, Hideo,Hayakawa, Takashi,Takehira, Katsuomi
, p. 1522 - 1526 (2007/10/02)
2,4,6-Trimethylphenol was effectively oxidized to trimethyl-p-benzoquinone with molecular oxygen in the presense of a catalytic amount of copper(II) chloride-amines in alcohol at ambient temperature.Various amines could be used as a co-catalyst in the presence of acids, and especially hydroxylamine hydrochloride and acetone oxime coupled with hydrochloric acid showed high activity. 2,6-Dimethyl-p-benzoquinone was also obtained from 2,6-dimethylphenol in good yield in this catalytic oxidation system.
A novel oxygenation of 2,3,6-trimethylphenol to trimethyl-p-benzoquinone by dioxygen with copper(II) chloride/amine hydrochloride catalyst
Takehira,Shimizu,Watanabe,Orita,Hayakawa
, p. 6691 - 6692 (2007/10/02)
2,3,6-Trimethylphenol was efficiently oxygenated to trimethyl-p-benzoquinone by molecular oxygen in the presence of catalytic amount of copper (II) chloride/amine hydrochloride in alcoholic solvent at ambient temperature.
A Novel Synthesis of Trimethyl-p-benzoquinone: Copper(II)-hydroxylamine catalysed Oxygenation of 2,3,6-Trimethylphenol with Dioxygen
Takehira, Katsuomi,Shimizu, Masao,Watanabe, Yoshihito,Orita, Hideo,Hayakawa, Takashi
, p. 1705 - 1706 (2007/10/02)
2,3,6-Trimethylphenol was efficiently oxygenated to trimethyl-p-benzoquinone with molecular oxygen in the presence of a catalytic amount of copper(II) chloride-hydroxylamine in an alcoholic solvent at ambient temperature.
