10396-80-2Relevant articles and documents
Catalytic Function of Cobalt(III) Complexes with N,N'-Disalicylideneethylenediamine on Oxygenation of t-Butylphenols
Aimoto, Yuko,Kanda, Wakako,Meguro, Sadatoshi,Miyahara, Yuji
, p. 646 - 650 (1985)
Catalytic oxygenation of t-butylphenols has been examined with the cobalt(III) complexes with N,N'-disalicylideneethylenediamine (H2salen), K, Na, K, PF6, and PF6.The CO3-complex showed a high catalytic activity while the other complexes a low or no catalytic activity.Based on electronic and ESR spectral investigation, it has been shown that the reaction is initiated by the direct oxidation of t-butylphenols by the CO3-complex through a phenolatocobalt(III) intermediate.
Rapid conversion of phenols to p-benzoquinones under acidic conditions with lead dioxide
Omura, Kanji
, p. 1145 - 1148 (1998)
Treatment of 4-unsubstituted and 4-halogenated phenols with PbO2 and 70% HClO4 in AcOH afforded the corresponding p-benzoquinones in fair to high yields. The oxidation of 4-substituted 2,6-di-tertbutylphenols 6 with PbO2 and 70% HClO4 in acetone gave 2,6-di-tert-butyl-p-benzoquinone (2).
The Oxidation of 2,6-Di-tert-butyl-4-methylphenol Using Hydrogen Peroxide-Heteropolyacid System
Shimizu, Masao,Orita, Hideo,Hayakawa, Takashi,Watanabe, Yoshihito,Takehira, Katsuomi
, p. 1835 - 1837 (1990)
The oxidation of 2,6-di-tert-butyl-4-methylphenol (1) with hydrogen peroxide in the presence of heteropolyacids was carried out in acetic acid to give 2,6-di-tert-butyl-4-hydroperoxy-4-methyl-2,5-cyclohexadien-1-one (2), 2,6-di-tert-butyl-4-hydroxy-4-methyl-2,5-cyclohexadien-1-one (3), and 2,6-di-tert-butyl-p-benzoquinone (4).Conversion of 2 into 4 under acidic conditions suggests that 2 could be a precursor of 4.The oxidation mechanism of phenols was discussed based on isolated intermediates.
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Nishinaga,A. et al.
, p. 2983 - 2988 (1979)
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Oxidation of substituted phenols with chlorine dioxide
Loginov,Chukicheva,Kuchin
, p. 1501 - 1503 (2011)
Chlorine dioxide was used to oxidize sterically hindered phenols and their derivatives (2,6-di-tert-butylphenol, 2,6-diisobornylphenol, 2,6-di-tert-butyl-4-methylphenol, 2,6-diisobornyl-4-methylphenol, and 3,5-diisobornyl-4-hydroxybenzaldehyde) in organic solvent. Pleiades Publishing, Ltd., 2011.
OXYDATION SELECTIVE EN PARA DES PHENOLS PAR UN COMPLEXE CUIVRIQUE OXYDANT
Capdevielle, Patrice,Maumy, Michel
, p. 5611 - 5614 (1983)
Oxidation of phenols by molecular oxygen in the presence of the μ-oxo cupric catalyst Cu4Cl4O2 (CH3CN)3 (A), can be selectively directed to give either oxidative coupling or para-hydroxylation (p-quinols or p-quinones) products by the choice of the (A)/(phenol) ratio.The mechanism is discussed and a -OH ligand transfer from CuII to the phenolic para position is proposed.
Continuous Process Improvement in the Manufacture of Carfilzomib, Part 1: Process Understanding and Improvements in the Commercial Route to Prepare the Epoxyketone Warhead
Dornan, Peter K.,Anthoine, Travis,Beaver, Matthew G.,Cheng, Guilong Charles,Cohen, Dawn E.,Cui, Sheng,Lake, William E.,Langille, Neil F.,Lucas, Susan P.,Patel, Jenil,Powazinik, William,Roberts, Scott W.,Scardino, Chris,Tucker, John L.,Spada, Simone,Zeng, Alicia,Walker, Shawn D.
, p. 481 - 489 (2020)
Epoxyketone 4 is an isolated intermediate in the manufacturing route to the commercial proteasome inhibitor carfilzomib (Kyprolis). Commercial process development and optimization efforts toward the preparation of epoxyketone 4 highlighted several opportunities for process improvement. In this article, three case studies are presented that demonstrate how a detailed understanding of the reaction mechanism led to improvements that increased the overall robustness of the process. In the first case study, the mechanism of racemization of an α-chiral enone was investigated, resulting in the development of an improved aqueous workup procedure. Next, the stability of a bleach/pyridine mixture used for the step 3 epoxidation reaction was studied, leading to the identification of pyridine as a key raw material and improved reaction conditions and control strategy to meet the conversion target. Finally, oxidized butylated hydroxytoluene (oBHT) was identified as an impurity arising from the use of BHT-stabilized tetrahydrofuran in steps preceding the oxidation. The process understanding obtained from these investigations led to the implementation of process improvements that improved the robustness of the process. The development of a second-generation route to 4 is the subject of part 2 in this series (DOI: 10.1021/acs.oprd.0c00052).
Nishinaga et al.
, p. 1291 (1974)
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Nishinaga,A. et al.
, p. 1820 - 1825 (1978)
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New insights into the reactivity of nitrogen dioxide with substituted phenols: A solvent effect
Astolfi, Paola,Panagiotaki, Maria,Greci, Lucedio
, p. 3052 - 3059 (2005)
Various alkyl-substituted phenols react readily with nitrogen dioxide (.NO2) in different solvents at room temperature. In all cases nitration is the major reaction and leads to the formation of mono- and dinitrophenols and 4-nitrocyclohexa-2,5-dienones from 2,4,6-tri-substituted phenols. Oxidation, dimerisation and, in one case, nitrosation are also observed. The reaction pathway followed changes according to the solvent and to the nature and the number of substituents on the phenolic ring. Wiley-VCH Verlag GmbH & Co. KGaA, 2005.
CsOH catalyzed aerobic oxidative synthesis of p-quinols from multi-alkyl phenols under mild conditions
Liang, Yu-Feng,Wu, Kai,Liu, Zhiqing,Wang, Xiaoyang,Liang, Yujie,Liu, Chenjiang,Jiao, Ning
, p. 1334 - 1339 (2015)
p-Quinols are ubiquitous structural motifs of various natural products and pharmaceutical compounds, and versatile building blocks in synthetic chemistry. The reported methods for the synthesis of p-quinol require stoichiometric amounts of oxidants. Molecular oxygen is considered as an ideal oxidant due to its natural, inexpensive, and environmentally friendly characteristics. During the ongoing research of C-H bond hydroxylation, we found that multi-alkyl phenols could react with molecular oxygen under mild conditions. Herein, we describe an efficient oxidative de-aromatization of multi-alkyl phenols to p-quinols. 1 atm of molecular oxygen was used as the oxidant. Many multi-alkyl phenols could react smoothly at room temperature. Isotopic labeling experiment was also performed, and the result proved that the oxygen atom in the produced hydroxyl group is from molecular oxygen.
Electrochemical Aerobic Oxidative Cleavage of (sp3)C-C(sp3)/H Bonds in Alkylarenes
Liu, Shuai,Liu, Zhong-Quan,Shen, Tong,Shen, Xu,Wang, Nengyong,Wu, Jintao,Yang, Le,Zhao, Jianyou
supporting information, p. 3286 - 3295 (2022/03/14)
An electrochemistry-promoted oxidative cleavage of (sp3)C-C(sp3)/H bonds in alkylarenes was developed. Various aryl alkanes can be smoothly converted into ketones/aldehydes under aerobic conditions using a user-friendly undivided cell setup. The features of air as oxidant, scalability, and mild conditions make them attractive in synthetic organic chemistry.
DBU/O2-Mediated Oxidation of Dienones
Athawale, Paresh R.,Kalmode, Hanuman P.,Reddy, D. Srinivasa
supporting information, p. 9200 - 9205 (2021/07/19)
Herein, we describe a DBU/O2-promoted novel method for oxidation of dienones to 2,6-dione derivatives. The reaction involves treatment of a dienone with DBU in acetonitrile employing molecular oxygen as the oxidant. Metal free conditions and an eco-friendly reagent are the striking features of this protocol. This transformation proceeds through a peroxide intermediate that upon Kornblum-DeLaMare rearrangement produces 2,6-diones. The method was successfully utilized for the synthesis of (±)-pleodendione with improved yields versus those of the traditional PDC-TBHP method.
