527-35-5Relevant articles and documents
Pentamethylphenyl (Ph*) and Related Derivatives as Useful Acyl Protecting Groups for Organic Synthesis: A Preliminary Study
Cheong, Choon Boon,Frost, James R.,Donohoe, Timothy J.
, p. 1828 - 1832 (2020/10/06)
A study of acyl protecting groups derived from the Ph? motif is reported. While initial studies indicated that a variety of functional groups were not compatible with the Br 2-mediated cleavage conditions required to release the Ph? group, strategies involving the use of different reagents or a modification of Ph? itself (Ph*OH) were investigated to solve this problem.
Deoxyalkylation of guaiacol using haggite structured V4O6(OH)4
Yan, Fei,Wen, Zhe,Wu, Kai,Cui, Kai,Mai, Fuhang,Ma, Zewei,Sang, Yushuai,Bai, Yunfei,Chen, Hong,Li, Yongdan
, p. 1922 - 1932 (2019/04/29)
When V2O5 is used for the deoxygenation of guaiacol in methanol, it is reduced in situ to haggite structured V4O6(OH)4. Guaiacol prevents further reduction of the haggite phase in methanol and haggite catalyzes the partial deoxygenation of guaiacol. Haggite is a metastable redox catalyst for the deoxygenation of guaiacol, which follows the reverse Mars-van Krevelen mechanism. In addition, haggite is also a Lewis acid catalyst and catalyzes the alkylation of guaiacol with methanol as the alkylation reagent. The main products of the guaiacol deoxyalkylation are 2,6-dimethylphenol, 2-methoxy-6-methylphenol, 2,4,6-trimethylphenol, 2,3,6-trimethylphenol, 2,3,5,6-tetramethylphenol and 6-methyl-2-tert-butylphenol. Oligomerization takes place during the reaction but it is reversible. When the reaction is performed at 300 °C for 6 h, the 83.5% total selectivity for alkylphenols is achieved with a 99.0% conversion.
Phenolic Oxidation Using H2O2 via in Situ Generated para-Quinone Methides for the Preparation of para-Spiroepoxydienones
McLaughlin, Michael F.,Massolo, Elisabetta,Cope, Thomas A.,Johnson, Jeffrey S.
supporting information, p. 6504 - 6507 (2019/09/04)
Phenols are attractive starting materials for the preparation of highly substituted cyclohexane rings via dearomative processes. Herein we report an efficient preparation of dearomatized 1-oxaspiro[2.5]octa-4,7-dien-6-ones (para-spiroepoxydienones) via the nucleophilic epoxidation of in situ generated para-quinone methides from 4-(hydroxymethyl)phenols using aqueous H2O2. The developed protocol bypasses the need for stoichiometric bismuth reagents or diazomethane, which are frequently deployed for p-spiroepoxydienone preparation. The p-spiroepoxydienones are further elaborated in numerous downstream complexity-building transformations.
Synthesis of phenols and aryl silyl ethers via arylation of complementary hydroxide surrogates
Reitti, Marcus,Gurubrahamam, Ramani,Walther, Melanie,Lindstedt, Erik,Olofsson, Berit
, p. 1785 - 1788 (2018/04/14)
Two transition-metal-free methods to access substituted phenols via the arylation of silanols or hydrogen peroxide with diaryliodonium salts are presented. The complementary reactivity of the two nucleophiles allows synthesis of a broad range of phenols without competing aryne formation, as illustrated by the synthesis of the anesthetic Propofol. Furthermore, silyl-protected phenols can easily be obtained, which are suitable for further transformations.
Experimental Investigation on Upgrading of Lignin-Derived Bio-Oils: Kinetic Analysis of Anisole Conversion on Sulfided CoMo/Al2O3 Catalyst
Rahimpour, Hamid Reza,Saidi, Majid,Rostami, Parisa,Gates, Bruce C.,Rahimpour, Mohammad Reza
, p. 702 - 713 (2016/09/28)
Kinetics of the hydroprocessing of anisole, a compound representative of lignin-derived bio-oils, catalyzed by a commercial sulfided CoMo/Al2O3, was determined at 8–20 bar pressure and 573–673 K with a once-through flow reactor. The catalyst was sulfided in an atmosphere of H2 + H2S prior to the measurement of its performance. Selectivity-conversion data were used as a basis for determining an approximate, partially quantified reaction network showing that hydrodeoxygenation (HDO), hydrogenolysis, and alkylation reactions take place simultaneously. The data indicate that these reactions can be stopped at the point where HDO is virtually completed and hydrogenation reactions (and thus H2 consumption) are minimized. Phenol was the major product of the reactions, with direct deoxygenation of anisole to give benzene being kinetically almost insignificant under our conditions. We infer that the scission of the Cmethyl–O bond is more facile than the scission of the Caromatic–O bond, so that the HDO of anisole likely proceeds substantially through the reactive intermediate phenol to give transalkylation products such as 2-methylphenol. The data determine rates of formation of the major primary products. The data show that if oxygen removal is the main processing goal, higher temperatures and lower pressures are favored.
CYCLIC PEROXIDE OXIDATION OF AROMATIC COMPOUND PRODUCTION AND USE THEREOF
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Page/Page column 9; 10, (2014/10/15)
The present invention provides a method for converting an aromatic hydrocarbon to a phenol by providing an aromatic hydrocarbon comprising one or more aromatic C-H bonds and one or more activated C-H bonds in a solvent; adding a phthaloyl peroxide to the solvent; converting the phthaloyl peroxide to a di-radical; contacting the di-radical with the one or more aromatic C-H bonds; oxidizing selectively one of the one or more aromatic C-H bonds in preference to the one or more activated C-H bonds; adding a hydroxyl group to the one of the one or more aromatic C-H bonds to form one or more phenols; and purifying the one or more phenols.
A protocol to generate phthaloyl peroxide in flow for the hydroxylation of arenes
Eliasen, Anders M.,Thedford, Randal P.,Claussen, Karin R.,Yuan, Changxia,Siegel, Dionicio
supporting information, p. 3628 - 3631 (2014/08/05)
A flow protocol for the generation of phthaloyl peroxide has been developed. This process directly yields phthaloyl peroxide in high purity (>95%) and can be used to bypass the need to isolate and recrystallize phthaloyl peroxide, improving upon earlier batch procedures. The flow protocol for the formation of phthaloyl peroxide can be combined with arene hydroxylation reactions and provides a method for the consumption of peroxide as it is generated to minimize the accumulation of large quantities of peroxide.
Metal-free oxidation of aromatic carbon-hydrogen bonds through a reverse-rebound mechanism
Yuan, Changxia,Liang, Yong,Hernandez, Taylor,Berriochoa, Adrian,Houk, Kendall N.,Siegel, Dionicio
, p. 192 - 196 (2013/08/23)
Methods for carbon-hydrogen (C-H) bond oxidation have a fundamental role in synthetic organic chemistry, providing functionality that is required in the final target molecule or facilitating subsequent chemical transformations. Several approaches to oxidizing aliphatic C-H bonds have been described, drastically simplifying the synthesis of complex molecules. However, the selective oxidation of aromatic C-H bonds under mild conditions, especially in the context of substituted arenes with diverse functional groups, remains a challenge. The direct hydroxylation of arenes was initially achieved through the use of strong Bronsted or Lewis acids to mediate electrophilic aromatic substitution reactions with super-stoichiometric equivalents of oxidants, significantly limiting the scope of the reaction. Because the products of these reactions are more reactive than the starting materials, over-oxidation is frequently a competitive process. Transition-metal-catalysed C-H oxidation of arenes with or without directing groups has been developed, improving on the acid-mediated process; however, precious metals are required. Here we demonstrate that phthaloyl peroxide functions as a selective oxidant for the transformation of arenes to phenols under mild conditions. Although the reaction proceeds through a radical mechanism, aromatic C-H bonds are selectively oxidized in preference to activated-H bonds. Notably, a wide array of functional groups are compatible with this reaction, and this method is therefore well suited for late-stage transformations of advanced synthetic intermediates. Quantum mechanical calculations indicate that this transformation proceeds through a novel addition-abstraction mechanism, a kind of 'reverse-rebound' mechanism as distinct from the common oxygen-rebound mechanism observed for metal-oxo oxidants. These calculations also identify the origins of the experimentally observed aryl selectivity.
Optimization of (2,3-dihydro-1-benzofuran-3-yl)acetic acids: Discovery of a non-free fatty acid-like, highly bioavailable G protein-coupled receptor 40/free fatty acid receptor 1 agonist as a glucose-dependent insulinotropic agent
Negoro, Nobuyuki,Sasaki, Shinobu,Mikami, Satoshi,Ito, Masahiro,Tsujihata, Yoshiyuki,Ito, Ryo,Suzuki, Masami,Takeuchi, Koji,Suzuki, Nobuhiro,Miyazaki, Junichi,Santou, Takashi,Odani, Tomoyuki,Kanzaki, Naoyuki,Funami, Miyuki,Morohashi, Akio,Nonaka, Masami,Matsunaga, Shinichiro,Yasuma, Tsuneo,Momose, Yu
experimental part, p. 3960 - 3974 (2012/07/28)
G protein-coupled receptor 40 (GPR40)/free fatty acid receptor 1 (FFA1) is a free fatty acid (FFA) receptor that mediates FFA-amplified glucose-stimulated insulin secretion in pancreatic β-cells. We previously identified (2,3-dihydro-1-benzofuran-3-yl)acetic acid derivative 2 as a candidate, but it had relatively high lipophilicity. Adding a polar functional group on 2 yielded several compounds with lower lipophilicity and little effect on caspase-3/7 activity at 30 μM (a marker of toxicity in human HepG2 hepatocytes). Three optimized compounds showed promising pharmacokinetic profiles with good in vivo effects. Of these, compound 16 had the lowest lipophilicity. Metabolic analysis of 16 showed a long-acting PK profile due to high resistance to β-oxidation. Oral administration of 16 significantly reduced plasma glucose excursion and increased insulin secretion during an OGTT in type 2 diabetic rats. Compound 16 (TAK-875) is being evaluated in human clinical trials for the treatment of type 2 diabetes.
Complexation of dichlorocarbene by methylanisoles
Moss, Robert A.,Wang, Lei,Odorisio, Christina M.,Krogh-Jespersen, Karsten
body text, p. 1467 - 1470 (2010/05/18)
Dichlorocarbene generated by laser flash photolysis of dichlorodiazirine readily forms UV-vis active π- and O-ylidic complexes with methylanisole derivatives.
