- Palladium-Catalyzed Asymmetric Markovnikov Hydroxycarbonylation and Hydroalkoxycarbonylation of Vinyl Arenes: Synthesis of 2-Arylpropanoic Acids
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Asymmetric hydroxycarbonylation is one of the most fundamental yet challenging methods for the synthesis of carboxylic acids. Herein, we reported the development of a palladium-catalyzed highly enantioselective Markovnikov hydroxycarbonylation of vinyl arenes with CO and water. A monodentate phosphoramidite ligand L6 plays vital role in the reaction. The reaction tolerates a range of functional groups, and provides a facile and atom-economical approach to an array of 2-arylpropanoic acids including several commonly used non-steroidal anti-inflammatory drugs. The catalytic system has also enabled an asymmetric Markovnikov hydroalkoxycarbonylation of vinyl arenes with alcohols to afford 2-arylpropanates. Mechanistic investigations suggested that the hydropalladation is irreversible and is the regio- and enantiodetermining step, while hydrolysis/alcoholysis is probably the rate-limiting step.
- Guan, Zheng-Hui,Ren, Zhi-Hui,Wang, Yuan,Yang, Hui-Yi,Yao, Ya-Hong,Zou, Xian-Jin
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supporting information
p. 23117 - 23122
(2021/09/18)
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- A general platinum-catalyzed alkoxycarbonylation of olefins
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Hydroxy- and alkoxycarbonylation reactions constitute important industrial processes in homogeneous catalysis. Nowadays, palladium complexes constitute state-of-the-art catalysts for these transformations. Herein, we report the first efficient platinum-catalysed alkoxycarbonylations of olefins including sterically hindered and functionalized ones. This atom-efficient catalytic transformation provides straightforward access to a variety of valuable esters in good to excellent yields and often with high selectivities. In kinetic experiments the activities of Pd- and Pt-based catalysts were compared. Even at low catalyst loading, Pt shows high catalytic activity.
- Beller, Matthias,Dühren, Ricarda,Franke, Robert,Ge, Yao,Huang, Weiheng,Jackstell, Ralf,Liu, Jiawang,Neumann, Helfried,Schneider, Carolin,Yang, Ji
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supporting information
p. 5235 - 5238
(2020/07/30)
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- Efficient palladium-catalyzed synthesis of 2-aryl propionic acids
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A flexible two-step, one-pot procedure was developed to synthesize 2-aryl propionic acids including the anti-inflammatory drugs naproxen and flurbiprofen. Optimal results were obtained in the presence of the novel ligand neoisopinocampheyldiphenylphosphine (NISPCPP) (9) which enabled the efficient sequential palladium-catalyzed Heck coupling of aryl bromides with ethylene and hydroxycarbonylation of the resulting styrenes to 2-aryl propionic acids. This cascade transformation leads with high regioselectivity to the desired products in good yields and avoids the need for additional purification steps.
- Neumann, Helfried,Sergeev, Alexey G.,Spannenberg, Anke,Beller, Matthias
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- Palladium-Catalyzed Alkoxycarbonylation of sec-Benzylic Ethers
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Herein, we report the palladium-catalyzed synthesis of 3-arylpropionate esters starting from secondary benzylic ethers. With this investigation it could be shown that ethers are suitable starting materials in addition to the established carbonylation reactions of olefins, alcohols, or aryl halides.
- Beller, Matthias,Jackstell, Ralf,Maes, Bert U. W.,Schneider, Carolin
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supporting information
(2020/02/25)
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- Iridium-Catalyzed α-Methylation of α-Aryl Esters Using Methanol as the C1 Source
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IrCl(cod)2]/dppe-catalyzed α-methylation of aryl esters using methanol as the C1 source was developed. This methylation process is useful in several fields including organic chemistry, biochemistry, and medicinal chemistry. Readily available methanol as methylation reagent was successfully adapted. The reaction processed high atom economy and efficient. By applying the reaction system, the synthesis method of naproxen was provided.
- Tsukamoto, Yuya,Itoh, Satoshi,Kobayashi, Masaki,Obora, Yasushi
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supporting information
p. 3299 - 3303
(2019/05/10)
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- Synthesis and Applications of Unquaternized C-Bound Boron Enolates
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A general and facile method to prepare unquaternized C-bound boron enolates by a ligand-controlled O-to-C isomerization is reported. Using this protocol, C-bound pinacolboron enolates have been isolated in pure form for the first time, and have been fully characterized by NMR spectroscopy and X-ray crystallography. In contrast to the general perception, such C-boron enolates are stable without coordinative saturation at the boron. Moreover, C-boron enolates present reactivities that are distinct from the O-boron enolates, and their applications in C-O and C-C bond formations are demonstrated.
- Ng, Elvis Wang Hei,Low, Kam-Hung,Chiu, Pauline
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supporting information
p. 3537 - 3541
(2018/03/21)
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- PYRETHROID COMPOUND, AND HAIR RESTORER AND HAIR RESTORER COMPOSITION COMPRISING THE SAME
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PROBLEM TO BE SOLVED: To provide a pyrethroid compound having hair growth effect. SOLUTION: The present invention provides a pyrethroid compound represented by general formula (1) [in general formula (1), R1 is selected from a hydrogen atom, a halogen atom, an azido group, an alkoxy group having 1 to 4 carbon atoms, and an alkyl group having 1 to 4 carbon atoms, R2 is selected from a methyl group, an ethyl group and an isopropyl group, R3 is selected from -C≡N, -C≡CH, -C≡C-CH3 and -CH=CH2, and R4 is selected from a methyl group, a phenyl group, a 2-methoxy ethyl group, a methoxymethyl group, and a propargyl group]. SELECTED DRAWING: None COPYRIGHT: (C)2017,JPOandINPIT
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- Stereodivergent coupling of aldehydes and alkynes via synergistic catalysis using Rh and Jacobsen's amine
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We report an enantioselective coupling between α-branched aldehydes and alkynes to generate vicinal quaternary and tertiary carbon stereocenters. The choice of Rh and organocatalyst combination allows for access to all possible stereoisomers with high enantio-, diastereo-, and regioselectivity. Our study highlights the power of catalysis to activate two common functional groups and provide access to divergent stereoisomers and constitutional structures.
- Cruz, Faben A.,Dong, Vy M.
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supporting information
p. 1029 - 1032
(2017/05/15)
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- Stereodivergent Coupling of Aldehydes and Alkynes via Synergistic Catalysis Using Rh and Jacobsen's Amine
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We report an enantioselective coupling between α-branched aldehydes and alkynes to generate vicinal quaternary and tertiary carbon stereocenters. The choice of Rh and organocatalyst combination allows for access to all possible stereoisomers with high ena
- Cruz, Faben A.,Dong, Vy M.
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supporting information
p. 1029 - 1032
(2021/09/04)
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- Palladium-Catalyzed Carbonylation of sec- and tert-Alcohols
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A general palladium-catalyzed synthesis of linear esters directly from sec- and tert-alcohols is described. Compared to the classic Koch–Haaf reaction, which leads to branched products, this new transformation gives the corresponding linear esters in high yields and selectivity. Key for this protocol is the use of an advanced palladium catalyst system with L2 (pytbpx) as the ligand. A variety of aliphatic and benzylic alcohols can be directly used and the catalyst efficiency for the benchmark reaction is outstanding (turnover number up to 89 000).
- Dong, Kaiwu,Sang, Rui,Liu, Jie,Razzaq, Rauf,Franke, Robert,Jackstell, Ralf,Beller, Matthias
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supporting information
p. 6203 - 6207
(2017/05/22)
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- A recyclable CO surrogate in regioselective alkoxycarbonylation of alkenes: Indirect use of carbon dioxide
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Herein, we report a Pd-catalysed alkoxycarbonylation of alkenes based on the use of a recyclable CO2 reduction product, the crystalline and air-stable N-formylsaccharin, as a CO surrogate. The carbonylation proceeds under ambient conditions in an exceptionally complementary regioselective fashion yielding the desired branched products from styrene derivatives and valuable linear esters from alkyl-substituted alkenes.
- Gehrtz,Hirschbeck,Fleischer
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supporting information
p. 12574 - 12577
(2015/08/06)
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- Various oxidative reactions with novel ion-supported (diacetoxyiodo) benzenes
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The oxidation of secondary alcohols and primary alcohols with two novel ion-supported (diacetoxyiodo)benzenes (IS-DIBs) A and B in the presence of a catalytic amount of 2,2,6,6-tetramethylpiperidine-1-oxyl radical (TEMPO) in dichloromethane at room temperature proceeded efficiently to provide the corresponding ketones and aldehydes, respectively, in good yields. The oxidative reaction of N,N-diisopropylbenzylamines with those IS-DIBs was also carried out to generate the corresponding aromatic aldehydes in good yields. In addition, the Hofmann rearrangement of primary amides in methanol under basic conditions and the oxidative 1,2-rearrangement of propiophenones in trimethyl orthoformate under acidic conditions with those IS-DIBs provided the corresponding methyl carbamates and methyl 2-arylpropanoates, respectively, in good yields. Moreover, treatment of acetophenones with those IS-DIBs in the presence of trifluoromethanesulfonic acid in acetonitrile generated the corresponding 5-aryl-2-methyloxazoles in good yields. In those five reactions, the desired products were obtained in good yields with high purity by simple extraction of the reaction mixture with diethyl ether and subsequent removal of the solvent from the extract. Moreover, ion-supported iodobenzenes, which were the co-products derived from IS-DIBs in the present oxidative reactions, were recovered in good yields and could be re-oxidized to IS-DIBs A and B for reuse in the same oxidative reactions.
- Iinuma, Masataka,Moriyama, Katsuhiko,Togo, Hideo
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p. 2961 - 2970
(2013/04/10)
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- Enantioselective hydrogenation of α-substituted acrylic acids catalyzed by iridium complexes with chiral spiro aminophosphine ligands
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Highly active: Iridium complexes with chiral spiro aminophosphine ligands were synthesized and applied as catalysts for the asymmetric hydrogenation of α-substituted acrylic acids (see scheme). The complexes were highly active catalysts, showing turnover frequencies of up to 6000 h-1, and catalyst loadings could be reduced to 0.01 mol %. Copyright
- Zhu, Shou-Fei,Yu, Yan-Bo,Li, Shen,Wang, Li-Xin,Zhou, Qi-Lin
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supporting information; body text
p. 8872 - 8875
(2012/10/08)
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- A novel synthetic route to 2-arylalkanoic acids by a ruthenium-catalyzed chemoselective oxidation of furan rings
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An efficient two-step synthesis of 2-arylalkanoic acids from 1-arylalkanols is described. Firstly, 1-arylalkylfuran derivatives were synthesized in high yields by the metal triflate catalyzed Friedel-Crafts alkylation of 2-methylfuran with 1-arylalkanols without employing anhydrous conditions. The chemoselective oxidation of the furan ring in 1-arylalkylfurans to carboxylic acid was then investigated. In a solvent system of hexane-EtOAc/H2O (1:3:4), the furan ring was selectively oxidized with 7 equivalents of NaIO 4 by using 0.5 mol% RuCl3 as catalyst to give 2-arylalkanoic acids in good yields. The selectivity of ruthenium oxidation was controlled by the solvent ratio of hexane-EtOAc. Georg Thieme Verlag Stuttgart.
- Noji, Masahiro,Sunahara, Haruka,Tsuchiya, Ken-Ichi,Mukai, Toru,Komasaka, Ayako,Ishii, Keitaro
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experimental part
p. 3835 - 3845
(2009/07/04)
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- METALLOPROTEASE INHIBITORS
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The present invention relates to amide containing aromatic MMP inhibiting compounds with a mono-amide heteroaromatic group, of formulas I and II:
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Page/Page column 79
(2008/06/13)
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- Oxidative rearrangements of arylalkanones with 1H-1-hydroxy-5-methyl-1,2,3-benziodoxathiole 3,3-dioxide, a 'green' analog of Koser's reagent
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Previous methods for the conversion of arylalkanones to alkyl 2-arylesters by oxidative rearrangement utilized reagents which either produced toxic metal salts or halogenated organics as by-products. In this report, 1H-1-hydroxy-5-methyl-1,2,3-benziodoxathiole 3,3-dioxide (HMBI) is used to effect this useful transformation, where the reduced iodine reagent is water-soluble and readily recycled.
- Justik, Michael W.
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p. 3003 - 3007
(2008/02/06)
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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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- Amido compounds and their use as pharmaceuticals
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The present invention relates to inhibitors of 11-β hydroxyl steroid dehydrogenase type 1, antagonists of the mineralocorticoid receptor (MR), and pharmaceutical compositions thereof. The compounds of the invention can be useful in the treatment of various diseases associated with expression or activity of 11-β hydroxyl steroid dehydrogenase type 1 and/or diseases associated with aldosterone excess.
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Page/Page column 42
(2010/02/15)
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- Palladium-catalyzed hydroesterification of styrene derivatives in the presence of ionic liquids
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The palladium-catalyzed hydroesterification of olefins occurs efficiently in a range of ionic liquid media. Selectivities ranging from 5-7:1 for the linear ester were obtained with styrene in a range of IL solvents. The use of ILs allowed the catalyst to be easily separated from the organic product by either extraction or distillation. The (Ph3P)2PdCl 2 precatalyst could be recovered unchanged from the ionic liquid phase. The IL/catalyst phase could be recycled five times with an average yield of 68%.
- Klingshirn, Marc A.,Rogers, Robin D.,Shaughnessy, Kevin H.
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p. 3620 - 3626
(2007/10/03)
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- Rational design of CH/π interaction sites in a basic resolving agent
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A novel synthetic basic resolving agent, cis-1-aminobenz[f]indan-2-ol (ABI), was rationally designed by introducing effective CH/π interaction sites to cis-1-aminoindan-2-ol (AI), whose chiral recognition ability has been reported from our laboratory. ABI was applicable to a wide variety of racemic arylalkanoic acids and showed moderate to excellent chiral recognition ability, which was obviously higher than that of AI. The fundamental and important role of CH/π interactions, such as tunable CH(sp2)/π and CH(sp 3)/π interactions, in the chiral recognition by ABI was revealed by X-ray crystallographic study.
- Kobayashi, Yuka,Kurasawa, Toshie,Kinbara, Kazushi,Saigo, Kazuhiko
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p. 7436 - 7441
(2007/10/03)
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- Hydroesterification Reactions with Palladium-Complexed PAMAM Dendrimers Immobilized on Silica
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Highly active, recyclable catalytic systems for the hydroesterification reaction of olefins with methanol and carbon monoxide were prepared by complexing various palladium species to generation zero through four PAMAM dendrimers immobilized on silica. The silica-dendrimer-Pd(PPh3) 2 complexes were the most facile recyclable catalysts and could be recycled four to six times by filtration under air. These catalysts show selectivity for the linear reaction product.
- Reynhardt, Jan P. K.,Alper, Howard
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p. 8353 - 8360
(2007/10/03)
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- Microbial deracemization of α-substituted carboxylic acids: Substrate specificity and mechanistic investigation
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A new enzymatic method for the preparation of optically active α-substituted carboxylic acids is reported. This technique is called deracemization reaction, which provides us with a route to obtain the enantiomerically pure compounds, theoretically in 100% yield starting from the racemic mixture. This means that the synthesis of a racemate is almost equal to the synthesis of the optically active compound, and this concept is entirely different from the commonly accepted one in the asymmetric synthesis. Using the growing cell system of Nocardia diaphanozonaria JCM3208, racemates of 2-aryl- and 2-aryloxypropanoic acid are deracemized smoothly and (R)-form-enriched products are recovered in high chemical yield (>50%). In addition, using optically active starting compounds and deuterated derivatives as well as inhibitors, we have disclosed the fact that a new type of enzyme takes part in this biotransformation, and that the reaction proceeds probably via the same mechanism as that in rat liver.
- Kato, Dai-Ichiro,Mitsuda, Satoshi,Ohta, Hiromichi
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p. 7234 - 7242
(2007/10/03)
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- Photochemical Rearrangement of α-Chloro-Propiophenones to α-Arylpropanoic Acids: Studies on Chirality Transfer and Synthesis of (S)-(+)-Ibuprofen and (S)-(+)-Ketoprofen
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A new single-step efficient photochemical approach for α-arylpropanoic acids (4) from α-chloro-propiophenones (5) is described.It involves carbonyl triplet excited state directed 1,2-aryl migration of the aryl group which has been found to be highly dependent upon the nature of the aryl substituent.The mode of the rearrangement is probed by the study of the photobehaviour of a set of optically active α-chloro-propiophenones.The results suggest that the nature of the carbonyl triplets (n, ?*/ ?, ?*) plays an important role in the chirality transfer.This method finds application in the synthesis of optically active ibuprofen (4e) and ketoprofen (26), though in moderate optical yields.
- Sonawane, Harikisan,Bellur, Nanjundiah S.,Kulkarni, Dilip G.,Ayyangar, Nagaraj R.
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p. 1243 - 1260
(2007/10/02)
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- A FACILE TRANSFORMATION OF ALKYL ARYL KETONES TO METHYL α-ARYLALKANOATES BY ANODIC OXIDATION IN THE PRESENCE OF IODINE OR IODO COMPOUNDS.
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Anodic oxidation of easily accessible alkyl aryl ketones 1 in trimethyl orthoformate containing a small amount of iodine or organo-iodo compounds gave methyl α-arylalkanoates 2 in high yields.
- Shono, Tatsuya,Matsumura, Yoshihiro,Katoh, Susumu,Fujita, Tetsuhiro,Kamada, Tohru
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p. 371 - 374
(2007/10/02)
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- A UNIQUE 1,2-SHIFT SELECTIVITY IN 2-HYDROXYPROPIOPHENONE DIMETHYLACETALS: GENERATION OF NEW METHODOLOGIES FOR METHYL-2-ARYLPROPANOATES AND 1,2-CARBONYL TRANSPOSITION
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α-Hydroxydimethylacetals I have been shown to undergo two different rearrangements involving highly selective 1,2-shifts under mild conditions.When treated with Ph3P/CCl4 in the presence of pyridine, I were cleanly transformed via 1,2-aryl shifts into methyl 2-arylpropanoates, an important class of antiinflammatory agents; a pronounced substituent effect has been observed in this rearrangement. On the other hand, treatment of I with catalytic amount of Ph3P/I2 in benzene furnished α-methoxy-α-aryl propan-2-ones in excellent yields and culminated in the development of a new methodology for 1,2-carbonyl transposition.
- Sonawane, H. R.,Nanjundiah, B. S.,Kulkarni, D. G.,Ahuja, Jaimala R.
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p. 7319 - 7324
(2007/10/02)
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- THE OXIDATRION OF ALDEHYDE BISULFITE ADDUCTS TO CARBOXYLIC ACIDS AND THEIR DERIVATIVES WITH DIMETHYLSULFOXIDE AND ACETIC ANHYDRIDE
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Bisulfite adducts which are readily formed from aldehydes are conveniently oxidized to carboxylic acids and derivatives by the action of DMSO/Ac2O followed by quenching with water, an alcohol or an amine.
- Wuts, Peter G. M.,Bergh, Carol L.
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p. 3995 - 3998
(2007/10/02)
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- A Lewis Acid Catalyzed 1,2 Aryl Shift in α-Haloalkyl Aryl Acetals: A Convenient Route to α-Arylalkanoic Acids
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A new method for the synthesis of α-arylalkanoic acids is given, based on Lewis acid promoted rearrangement of acetals of primary and secondary α-haloalkyl aryl ketones (halo = Br, Cl) in hydrocarbon solvents.The reaction is selective, providing the esters of α-arylalkanoic acids in almost quantitative yields.The ability of "soft and borderline" Lewis acids in activating the carbon-halogen bond is compared with that of silver salts.The reaction mechanism is discussed.The present synthesis has been applied to some α-arylpropionic acids well-known as antiinflammatory drugs.
- Castaldi, Graziano,Belli, Aldo,Uggeri, Fulvio,Giordano, Claudio
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p. 4658 - 4661
(2007/10/02)
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- Process for preparing arylalkanoic acid derivatives
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2-Aryl-C3 to C6 -alkanoate esters are prepared economically by reacting an enol ether of an aryl alkyl ketone with a trivalent thallium salt in an organic solvent. The ester intermediate product is then converted to the corresponding 2-aryl-C3 to C6 -alkanoic acid or salt thereof. The aryl group is selected so the resulting acid product will be a useful compound such as an anti-inflammatory, analgesic and anti-pyretic drug or agriculturally useful product. Examples of drug acids which can be made by this process include ibuprofen, flurbiprofen, fenoprofen and naproxen and the like.
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