- Discovery of novel modulators for the PPARα (peroxisome proliferator activated receptor α): Potential therapies for nonalcoholic fatty liver disease
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Nonalcoholic fatty liver disease (NAFLD) is a severe liver disease causing serious liver complications, including nonalcoholic steatohepatitis (NASH). Nuclear receptor PPARα (peroxisome proliferator-activated receptor α) has drawn special attention recently as a potential developmental drug target to treat type-2 diabetes and related diseases due to its unique functions in regulating lipid metabolism, promoting triglyceride oxidation, and suppressing hepatic inflammation, raising interest in PPARα agonists as potential therapies for NAFLD. However, how PPARα coordinates potential treatment of NAFLD and NASH between various metabolic pathways is still obscure. Here, we show that the DY series of novel selective PPARα modulators activate PPARα by up-regulating PPARα target genes directly involved in NAFLD and NASH. The design, synthesis, docking studies, and in vitro and in vivo evaluation of the novel DY series of PPARα agonists are described.
- Yu, Donna D.,Van Citters, Gregg,Li, Hongzhi,Stoltz, Brian M.,Forman, Barry M.
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Read Online
- Copper-Catalyzed Conjugate Addition of Carbonyls as Carbanion Equivalent via Hydrazones
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Copper-catalyzed conjugate addition is a classic method for forming new carbon-carbon bonds. However, copper has never showed catalytic activity for umpolung carbanions in hydrazone chemistry. Herein, we report a facile conjugate addition of hydrazone catalyzed by readily available copper complexes at room temperature. The employment of mesitylcopper(I) and electron-rich phosphine bidentate ligand is a key factor affecting reactivity. The reaction allows various aromatic hydrazones to react with diverse conjugated compounds to produce 1,4-adducts in yields of about 20 to 99%.
- Luo, Siyi,Peng, Marie,Querard, Pierre,Li, Chen-Chen,Li, Chao-Jun
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p. 13111 - 13117
(2021/09/18)
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- An Iron-Mesoionic Carbene Complex for Catalytic Intramolecular C-H Amination Utilizing Organic Azides
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The synthesis of N-heterocycles is of paramount importance for the pharmaceutical industry. They are often synthesized through atom economic and environmentally unfriendly methods, generating significant waste. A less explored, but greener, alternative is
- Albrecht, Martin,Keilwerth, Martin,Meyer, Karsten,Pividori, Daniel M.,Stroek, Wowa
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supporting information
p. 20157 - 20165
(2021/12/09)
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- Two-way homologation of aliphatic aldehydes: Both one-carbon shortening and lengthening via the same intermediate
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Aliphatic aldehydes can be homologated to both one-carbon shorter and one-carbon longer homologous carbonyl compounds through the 2–4 steps of reactions via the same intermediates, β,γ-unsaturated α-nitrosulfones, prepared from the proline-catalyzed sequential reactions of several aliphatic aldehydes with phenylsulfonylnitromethane. While the oxidative cleavage of the key intermediates gave one-carbon less homologous carbonyl compounds, the reduction of the same key intermediates followed by an oxidation produced one-carbon more homologous carbonyl compounds.
- Yoo, Jae Won,Seo, Youngran,Park, Jong Beom,Kim, Young Gyu
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- Palladium catalyzed hydroesterification of substituted alkenes under microwave conditions
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While several catalyst systems have been utilized in the hydroesterification or methoxycarbonylation of alkenes or equivalent substrates, these reactions are conventionally performed in autoclave reactor systems under high CO pressure (20-70 bar) and thermal heating (70 - 110 oC). In this paper, the first methoxycarbonylation reactions performed in a microwave reactor fitted with a gas-Addition accessory system are reported on and compared to the same reactions performed under conventional heating in an autoclave reactor. Thus 1-octene, styrene, allylbenzene, o-and p-methoxyallylbenzene and β-methylstyrene were subjected to methoxycarbonylation over a palladium acetate-aluminum triflate catalyst system at 12 bar and 95 oC. Results obtained indicated the methoxycarbonylation of these alkenes to be much faster under microwave conditions when compared to conventional heating and improvements in conversion ranged between 3 and 5% for the more reactive substrates (1-octene and styrene) and 6 - 20% for the allylbenzenes and β-methylstyrene.
- Du Plessis, Maretha,Marais, Charlene,Bezuidenhoudt, Barend C. B.
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supporting information
p. 40 - 48
(2020/09/16)
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- Efficient C-H Amination Catalysis Using Nickel-Dipyrrin Complexes
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A dipyrrin-supported nickel catalyst (AdFL)Ni(py) (AdFL: 1,9-di(1-adamantyl)-5-perfluorophenyldipyrrin; py: pyridine) displays productive intramolecular C-H bond amination to afford N-heterocyclic products using aliphatic azide substrates. The catalytic amination conditions are mild, requiring 0.1-2 mol% catalyst loading and operational at room temperature. The scope of C-H bond substrates was explored and benzylic, tertiary, secondary, and primary C-H bonds are successfully aminated. The amination chemoselectivity was examined using substrates featuring multiple activatable C-H bonds. Uniformly, the catalyst showcases high chemoselectivity favoring C-H bonds with lower bond dissociation energy as well as a wide range of functional group tolerance (e.g., ethers, halides, thioetheres, esters, etc.). Sequential cyclization of substrates with ester groups could be achieved, providing facile preparation of an indolizidine framework commonly found in a variety of alkaloids. The amination cyclization reaction mechanism was examined employing nuclear magnetic resonance (NMR) spectroscopy to determine the reaction kinetic profile. A large, primary intermolecular kinetic isotope effect (KIE = 31.9 ± 1.0) suggests H-atom abstraction (HAA) is the rate-determining step, indicative of H-atom tunneling being operative. The reaction rate has first order dependence in the catalyst and zeroth order in substrate, consistent with the resting state of the catalyst as the corresponding nickel iminyl radical. The presence of the nickel iminyl was determined by multinuclear NMR spectroscopy observed during catalysis. The activation parameters (ΔH? = 13.4 ± 0.5 kcal/mol; ΔS?= -24.3 ± 1.7 cal/mol·K) were measured using Eyring analysis, implying a highly ordered transition state during the HAA step. The proposed mechanism of rapid iminyl formation, rate-determining HAA, and subsequent radical recombination was corroborated by intramolecular isotope labeling experiments and theoretical calculations.
- Betley, Theodore A.,Clarke, Ryan M.,Dong, Yuyang,Porter, Gerard J.
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supporting information
p. 10996 - 11005
(2020/07/08)
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- A metal-free desulfurizing radical reductive C-C coupling of thiols and alkenes
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An intermolecular reductive C-C coupling of electrophilic alkyl radicals and alkenes has been developed. Thiols were used as both hydrogen-donating reagents and alkyl radical precursors in the presence of triethyl phosphite and radical initiator. A wide range of alkenes, including styrenes, and aliphatic olefins were well tolerated in this transformation. Mechanistic studies indicated that a phosphite promoted radical desulfurization of thiols to access electrophilic alkyl radicals and a radical chain propagation process may be involved in this transformation.
- Qin, Qixue,Wang, Weijing,Zhang, Cheng,Song, Song,Jiao, Ning
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supporting information
p. 10583 - 10586
(2019/09/06)
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- Reductive C-C Coupling by Desulfurizing Gold-Catalyzed Photoreactions
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[Au2(μ-dppm)2]Cl2-mediated photocatalysis reactions are usually initiated by ultraviolet A (UVA) light; herein, an unreported system using blue light-emitting diodes (LEDs) as excitation light source was found. The red shift of the absorption wavelength originates from the combination of [Au2(μ-dppm)2]Cl2 and ligand (Ph3P or mercaptan). On the basis of this finding, a gold-catalyzed reductive desulfurizing C-C coupling of electrophilic radicals and styrenes mediated by blue LEDs is presented, a coupling which cannot be efficiently accessed by previously reported methods. This mild and highly efficient C-C bond formation strategy uses mercaptans both as electron-deficient alkyl radical precursor as well as the hydrogen source. Two examples of amino acids have also been modified by using this strategy. Moreover, this methodology could be applied in polymer synthesis. Gram-scale synthesis and mechanistic insights into this transformation are also presented.
- Zhang, Lumin,Si, Xiaojia,Yang, Yangyang,Witzel, Sina,Sekine, Kohei,Rudolph, Matthias,Rominger, Frank,Hashmi, A. Stephen K.
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p. 6118 - 6123
(2019/07/03)
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- PEROXISOME PROLIFERATOR-ACTIVATED RECEPTOR AGONISTS
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Disclosed herein, inter alia, are compositions and methods useful for treating liver diseases and metabolic diseases.
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Paragraph 0315
(2019/03/30)
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- Catalytic C-H Amination Mediated by Dipyrrin Cobalt Imidos
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Reduction of (ArL)CoIIBr (ArL = 5-mesityl-1,9-(2,4,6-Ph3C6H2)dipyrrin) with potassium graphite afforded the novel CoI synthon (ArL)CoI. Treatment of (ArL)CoI with a stoichiometric amount of various alkyl azides (N3R) furnished three-coordinate CoIII alkyl imidos (ArL)Co(NR), as confirmed by single-crystal X-ray diffraction (R: CMe2Bu, CMe2(CH2)2CHMe2). The exclusive formation of four-coordinate cobalt tetrazido complexes (ArL)Co(κ2-N4R2) was observed upon addition of excess azide, inhibiting any subsequent C-H amination. However, when a weak C-H bond is appended to the imido moiety, as in the case of (4-azido-4-methylpentyl)benzene, intramolecular C-H amination kinetically outcompetes formation of the corresponding tetrazene species to generate 2,2-dimethyl-5-phenylpyrrolidine in a catalytic fashion without requiring product sequestration. The imido (ArL)Co(NAd) exists in equilibrium in the presence of pyridine with a four-coordinate cobalt imido (ArL)Co(NAd)(py) (Ka = 8.04 M-1), as determined by 1H NMR titration experiments. Kinetic studies revealed that pyridine binding slows down the formation of the tetrazido complex by blocking azide coordination to the CoIII imido. Further, (ArL)Co(NR)(py) displays enhanced C-H amination reactivity compared to that of the pyridine-free complex, enabling higher catalytic turnover numbers under milder conditions. The mechanism of C-H amination was probed via kinetic isotope effect experiments [kH/kD = 10.2(9)] and initial rate analysis with para-substituted azides, suggesting a two-step radical pathway. Lastly, the enhanced reactivity of (ArL)Co(NR)(py) can be correlated to a higher spin-state population, resulting in a decreased crystal field due to a geometry change upon pyridine coordination.
- Baek, Yunjung,Betley, Theodore A.
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supporting information
p. 7797 - 7806
(2019/05/22)
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- A Lewis Base Catalysis Approach for the Photoredox Activation of Boronic Acids and Esters
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We report herein the use of a dual catalytic system comprising a Lewis base catalyst such as quinuclidin-3-ol or 4-dimethylaminopyridine and a photoredox catalyst to generate carbon radicals from either boronic acids or esters. This system enabled a wide range of alkyl boronic esters and aryl or alkyl boronic acids to react with electron-deficient olefins via radical addition to efficiently form C?C coupled products in a redox-neutral fashion. The Lewis base catalyst was shown to form a redox-active complex with either the boronic esters or the trimeric form of the boronic acids (boroxines) in solution.
- Lima, Fabio,Sharma, Upendra K.,Grunenberg, Lars,Saha, Debasmita,Johannsen, Sandra,Sedelmeier, Joerg,Van der Eycken, Erik V.,Ley, Steven V.
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supporting information
p. 15136 - 15140
(2017/11/20)
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- Substituted 4-oxo-crotonic acid derivatives as a new class of protein kinase B (PknB) inhibitors: synthesis and SAR study
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Protein kinase B (PknB) is an essential serine/threonine protein kinase required for Mycobacterium tuberculosis (M. tb) cell division and cell-wall biosynthesis. A high throughput screen using PknB identified a (E)-4-oxo-crotonic acid inhibitor, named YH-8, which was used as a scaffold for SAR investigations. A significant improvement in enzyme affinity was achieved. The results indicated that the α,β-unsaturated ketone scaffold and “trans-” configuration are essential for the activity against PknB. And compounds with an aryl group, especially with electron-withdrawing substituents on benzene ring, exhibited four fold potency than that of YH-8.
- Xu, Changliang,Bai, Xiaoguang,Xu, Jian,Ren, Jinfeng,Xing, Yun,Li, Ziqiang,Wang, Juxian,Shi, Jingjing,Yu, Liyan,Wang, Yucheng
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p. 4763 - 4775
(2017/02/05)
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- Synthesis of Ketones and Esters from Heteroatom-Functionalized Alkenes by Cobalt-Mediated Hydrogen Atom Transfer
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Cobalt bis(acetylacetonate) is shown to mediate hydrogen atom transfer to a broad range of functionalized alkenes; in situ oxidation of the resulting alkylradical intermediates, followed by hydrolysis, provides expedient access to ketones and esters. By modification of the alcohol solvent, different alkyl ester products may be obtained. The method is compatible with a number of functional groups including alkenyl halides, sulfides, triflates, and phosphonates and provides a mild and practical alternative to the Tamao-Fleming oxidation of vinylsilanes and the Arndt-Eistert homologation.
- Ma, Xiaoshen,Herzon, Seth B.
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p. 8673 - 8695
(2016/10/17)
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- Parameters Influencing Reactivity and Regioselectivity in the Methoxycarbonylation of Arylalkenes
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Previous research showed that the steric bulk, electronic character, and bite angle of the ligand have an influence on both the catalyst activity and regioselectivity of hydroformylation and hydroesterification reactions. However, little is known in this regard about the influence of the steric and electronic environment around the double bond of the substrate. A variety of arylalkenes were therefore subjected to methoxycarbonylation to investigate the steric and electronic effects of substituents on the aromatic ring of the substrate on the regioselectivity and reactivity in the methoxycarbonylation reaction of these substrates with a Pd(II)/Al(OTf)3/Ph3P catalyst system.
- Du Plessis, Maretha,Marais, Charlene,Bezuidenhoudt, Barend C. B.
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p. 557 - 565
(2016/02/14)
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- Continuous UV-Flow Microsystem for Efficient Radical Generation from Organotrifluoroborates by Photoredox Catalysis
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An efficient continuous-flow protocol for C–O and C–C bond formation from organoborates by photoredox catalysis under UV irradiation was explored. The combination of a cyclometalated iridium photocatalyst, high-power UV light-emitting diode irradiation, and microreactor technology resulted in very efficient radical generation. The flow device enabled determination of highly accurate kinetic data that allowed the observation of good correlations with the standard Hammett σ (–0.26 to 0.227) values for a wide variety of substituents on the benzyl moiety (? = –4.70, R2= 0.98). Good to excellent yields were obtained for a variety of substrates by applying significantly short residence times.
- El Achi, Nassim,Penhoat, Ma?l,Bakkour, Youssef,Rolando, Christian,Chausset-Boissarie, La?titia
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supporting information
p. 4284 - 4288
(2016/09/13)
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- Metal-Free Enantioselective Oxidative Arylation of Alkenes: Hypervalent-Iodine-Promoted Oxidative C?C Bond Formation
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The enantioselective oxyarylation of (E)-6-aryl-1-silyloxylhex-3-ene was achieved using a lactate-based chiral hypervalent iodine(III) reagent in the presence of boron trifluoride diethyl etherate. The silyl ether promotes the oxidative cyclization, and enhances the enantioselectivity. In addition, the corresponding aminoarylation was achieved.
- Shimogaki, Mio,Fujita, Morifumi,Sugimura, Takashi
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supporting information
p. 15797 - 15801
(2016/12/16)
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- Pd-Catalyzed Regioselective Alkoxycarbonylation of 1-Alkenes Using a Lewis Acid [SnCl2 or Ti(OiPr)4] and a Phosphine
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The phosphine ligand mediated palladium catalyzed alkoxycarbonylation of alkenes was investigated with the objective of attaining good linear selectivity for the ester. The effect of various parameters such as solvents, additives, palladium precursors, CO pressures, and alkenes of various structural complexities were examined. The results revealed the importance of using a Lewis acid such as SnCl2 or Ti(OiPr)4 in combination with a monodentate ligand such CYTOP 292 or P(p-anisyl)3 to enhance the regioselectivity for the linear isomers in the range of 70-96%.
- Amézquita-Valencia, Manuel,Achonduh, George,Alper, Howard
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p. 6419 - 6424
(2015/06/30)
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- Visible light-induced selective generation of radicals from organoborates by photoredox catalysis
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A new strategy for the generation of carbon-centered radicals via oxidation of alkyl-, allyl-, benzyl- and arylborates by visible-light-driven single electron transfer (SET) photoredox catalysis has been established. The generated radicals smoothly react with TEMPO and electron-deficient alkenes to afford C-O and C-C coupling products, respectively. In this radical initiating system, cyclic organo(triol)borates turn out to be useful radical precursors.
- Yasu, Yusuke,Koike, Takashi,Akita, Munetaka
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supporting information
p. 3414 - 3420
(2013/02/25)
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- Highly regioselective anti-markovnikov palladium-borate-catalyzed methoxycarbonylation reactions: Unprecedented results for aryl olefins
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(Chemical Equation Presented) A general, highly efficient and regioselective methoxycarbonylation, by means of a palladium-salicylicborate- catalyzed protocol, of terminal alkyl and aryl olefins is described. The substrates include aliphatic alkenes, allylbenzenes, and styrene derivatives. The yields are very good (60-92%) and the regioselectivity, in favor of the linear ester, is up to quantitative - unprecedented in the case of styrenes.
- Vieira, Tiago O.,Green, Mike J.,Alper, Howard
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p. 6143 - 6145
(2007/10/03)
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- A facile synthesis of di-O-methyl centrolobol
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A facile route to (±)di-O-methyl centrolobol 4 has been explored starting from 4-oxo-4-(4-methoxyphenyl) butanoic acid 7 and 4-methoxycinnamic acid 13.
- Panda, Atulya Kumar
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p. 372 - 375
(2007/10/03)
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- AMINE-BASED AND AMIDE-BASED INHIBITORS OF SEMICARBAZIDE-SENSITIVE AMINE OXIDASE (SSAO) ENZYME ACTIVITY AND VAP-1 MEDIATED ADHESION USEFUL FOR TREATMENT OF DISEASES
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Compositions and methods are disclosed for inhibiting semicarbazide-sensitive amine oxidase (SSAO), also known as vascular adhesion protein-1 (VAP-1). The compounds disclosed are amine-containing and amide-containing compounds. The compounds and compositions are useful for treatment of diseases, including inflammation, inflammatory diseases and autoimmune disorders.
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Page/Page column 100
(2010/02/13)
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- Peroxisome proliferator activated receptor alpha agonists
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The present invention is directed to compounds represented by the following structural formula, and pharmaceutically acceptable salts, solvates and hydrates thereof, R1 is a substituted or unsubstituted group selected from C1-C8 alky
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- Regioselective intramolecular oxidation of phenols and anisoles by dioxiranes generated in situ
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A novel method for regioselective oxidation of phenols and anisoles has been developed in which dioxiranes, generated in situ from ketones and Ozone, oxidize phenol derivatives in an intramolecular fashion. A series of ketones with electron-withdrawing groups, such as CF3, COOMe, and CH2Cl, were attached to phenols, anisoles, or aryl rings via a C2 or C3 methylene linker. In a homogeneous solvent system of CH3CN and H2O, oxidation of phenol derivatives 1-10 afforded spiro 2-hydroxydienones in 24-55% yields regardless of the presence of other substituents (ortho Me, meta Me or Br) on the aryl ring and the length of the linker. Experimental evidences were provided to support the mechanism that involves a regioselective π bond epoxidation of aryl rings followed by epoxide rearrangement and hemiketal formation.
- Yang, Dan,Wong, Man-Kin,Yan, Zheng
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p. 4179 - 4184
(2007/10/03)
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- Synthesis of an intermediate, 7,8-dimethyl-2-tetralone, for occidol isomer-I and occidol isomer-II
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Anisole is succinoylated with succinic anhydride to yield 3-(p-methoxybenzoyl) propionic acid 3.The acid on Clemmensen reduction gives 4-(p-methoxy phenyl) butyric acid 4 which on esterification affords methyl 4-(p-methoxy-phenyl)butyrate 5.The ester 5 on reaction with methyl-magnesium iodide gives 5-(p-methoxyphenyl)-2-methyl-pentan-2-ol 6 which is cyclised with PPA to furnish 7-methoxy-1,1-dimethyltetralin 7.The tetralin 7 undergoes aromatization with p-chloranil or DDQ to afford 7-methoxy-1,2-dimethyl naphthalene 8, tike reduction of which with sodium in liquid ammonia as welt as with sodium in ethanol yields 7,8-dimethyl-2-tetralone 10.
- Bachule, M. T.,Mane, R. B.
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p. 281 - 284
(2007/10/03)
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- Tetramethylethylene diamine/trimethylsilyl chloride mediated addition of benzyl copper reagents to α,β-unsaturated esters
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Several benzylic copper reagents, benzylcopper, 4-methoxybenzylcopper and 1-phenylethylcopper, facilitate the conjugate addition of the corresponding benzyl ligands to α,β-enoates in the presence of tetramethylethylene diamine and trimethylsilyl chloride in high yields.
- Van Heerden, Pieter S.,Bezuidenhoudt, Barend C. B.,Ferreira, Daneel
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p. 12313 - 12322
(2007/10/03)
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