- Asymmetric Catalytic Epoxidation of Terminal Enones for the Synthesis of Triazole Antifungal Agents
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An enantioselective epoxidation of α-substituted vinyl ketones was realized to construct the key epoxide intermediates for the synthesis of various triazole antifungal agents. The reaction proceeded efficiently in high yields with good enantioselectivities by employing a chiral N,N′-dioxide/ScIII complex as the chiral catalyst and 35% aq. H2O2 as the oxidant. It enabled the facile transformation for optically active isavuconazole, efinaconazole, and other potential antifungal agents.
- Feng, Xiaoming,He, Qianwen,Liu, Xiaohua,Zhang, Dong,Zhang, Fengcai
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supporting information
p. 6961 - 6966
(2021/09/11)
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- INHIBITING CYCLIC AMP-RESPONSIVE ELEMENT-BINDING PROTEIN (CREB)
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The present disclosure is directed to inhibitors of the CBP/p300 family of bromodomains. The compounds can be useful in the treatment of disease or disorders associated with the inhibition of the CBP/p300 family of bromodomains. For instance, the disclosure is concerned with compounds and compositions for inhibition of the CBP/p300 family of bromodomains, methods of treating diseases or disorders associated with the inhibition of CBP/p300 family of bromodomains (e.g., certain forms of cancer), and methods of synthesis of these compounds.
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- An Efficient Palladium-Catalyzed α-Arylation of Acetone below its Boiling Point
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The monoarylation of acetone is a powerful transformation, but is typically performed at temperatures significantly in excess of its boiling point. Conditions described for performing the reaction at ambient temperatures led to significant dehalogenation when applied to a complex aryl halide. We describe our attempts to overcome both issues in the context of our drug-discovery program.
- Ledgard, Andrew J.,Martin, Fionna M.,Mutton, Simon P.,Richardson, Jeffery,Walton, Lesley
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- Enantioselective synthesis of β-substituted chiral allylic amines: Via Rh-catalyzed asymmetric hydrogenation
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An asymmetric mono-hydrogenation of 2-acetamido-1,3-dienes catalyzed by a Rh-DuanPhos complex has been developed. This approach provides easy access to chiral allylic amines with excellent enantioselectivities and high regioselectivities. The products are valuable chiral building blocks for pharmaceuticals.
- Wang, Qingli,Gao, Wenchao,Lv, Hui,Zhang, Xumu
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supporting information
p. 11850 - 11853
(2016/10/07)
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- Direct Asymmetric Reductive Amination for the Synthesis of Chiral β-Arylamines
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The highly efficient and direct asymmetric reductive amination of arylacetones catalyzed by an iridium complex for the preparation of enantiomerically pure β-arylamines is described. The monodentate phosphoramidite ligand exhibits superb reactivity (TONs of up to 20 000) and enantioselectivity (up to 99 % ee). Additives played important roles in this reductive coupling reaction. Asymmetric reductive coupling of a ketone and an amine is a straightforward and atom-economic approach for preparing optically enriched amines. The highly efficient and direct asymmetric reductive amination of arylacetones, catalyzed by an iridium complex, supplies enantiomerically pure β-arylamines. The new phosphoramidite ligands reported show superb reactivity and enantioselectivity in this reductive coupling. M.S.=molecular sieves, TFA=trifluoroacetic acid.
- Huang, Haizhou,Liu, Xiaoyan,Zhou, Le,Chang, Mingxin,Zhang, Xumu
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supporting information
p. 5309 - 5312
(2016/04/26)
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- Palladium-catalyzed mono-α-arylation of acetone with aryl imidazolylsulfonates
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Set the ace(tone): A palladium catalyst derived from the bidentate XantPhos ligand and Pd(OAc)2 has enabled broadly applicable mono-α-arylations of acetone to be performed with air- and moisture-stable aryl imidazolylsulfonates as most user-friendly electrophiles (see scheme). Copyright
- Ackermann, Lutz,Mehta, Vaibhav P.
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supporting information; experimental part
p. 10230 - 10233
(2012/09/22)
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- Palladium-catalyzed mono-α-arylation of acetone with aryl halides and tosylates
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We report the first example of selective Pd-catalyzed mono-α- arylation of acetone employing aryl chlorides, bromides, iodides, and tosylates. The use of appropriately designed P,N-ligands proved to be the key to controlling the reactivity and selectivity. The reaction affords good yields with substrates containing a range of functional groups at modest Pd loadings using Cs2CO3 as the base and employing acetone as both a reagent and the solvent.(Figure Presented)
- Hesp, Kevin D.,Lundgren, Rylan J.,Stradiotto, Mark
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supporting information; experimental part
p. 5194 - 5197
(2011/06/10)
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- Efficient synthesis of chiral β-arylisopropylamines by using catalytic asymmetric hydrogenation
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(Chemical Equation Presented) Direct condensation of β-arylketones with acetamide afforded both Z and E enamides. The Z-configured substrates underwent hydrogenation with excellent enantioselectivity by using the Rh/tang-phos catalytic system (see scheme; tangphos = 1,1′-di-tert-butyl- [2,2′]-diphospholanyl). The product β-arylisopropylamines are important precursors to several drugs.
- Chen, Jian,Zhang, Weicheng,Geng, Huiling,Li, Wei,Hou, Guohua,Lei, Aiwen,Zhang, Xumu
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supporting information; experimental part
p. 800 - 802
(2009/05/06)
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- Facile synthesis of 1-aryl-2-propanones from aromatic amine
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A facile synthesis of aryl propanones using aromatic amines as precursors, via an improved Meerwein arylation reaction under mild conditions, is reported. Copyright Taylor & Francis Group, LLC.
- Li, Li,Chen, Hongbiao,Lin, Yuanbin
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p. 985 - 991
(2007/10/03)
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- An Effective System to Synthesize Arylacetones. Substrate-ionic Liquid-ultrasonic Irradiation
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Manganese(III) acetate-promoted aromatic acetonylation has been accomplished with ultrasonic irradiation in ionic liquids, [N-n-pentyl-4- picolinium] [closo-CB11H12] (1), [OMIM] [BF4] and [BMIM] [PF6] in 62-93% yields, with excellent chemical selectivity.
- Yinghuai, Zhu,Bahnmueller, Stefan,Hosmane, Narayan S.,Maguire, John A.
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p. 730 - 731
(2007/10/03)
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- Tetrahydrothienopyridine derivatives, furo and pyrrolo analogs thereof and their preparation and uses for inhibiting blood platelet aggregation
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Compounds of formula (I): STR1 wherein: R1 is hydrogen, alkyl, halogen, haloalkyl, hydroxy, alkoxy, haloalkoxy, alkylthio, haloalkylthio, amino, alkanoyl, haloalkanoyl, carboxy, alkoxycarbonyl, carbamoyl, cyano, nitro, alkanesulfonyl, haloalkanesulfonyl or sulfamoyl; R2 is optionally substituted alkanoyl, optionally substituted alkenoyl, optionally substituted cycloalkylcarbonyl, substituted benzoyl, or 5,6-dihydro-1,4,2-dioxazin-3-yl; R3 is hydrogen, hydroxy, optionally substituted alkoxy, aralkyloxy, alkanoyloxy, alkenoyloxy, cycloalkylcarbonyloxy, arylcarbonyloxy, alkoxycarbonyloxy, aralkyloxycarbonylxy, phthalidyloxy, (5-methyl-2-oxo-1,3-dioxolen-4-yl)methoxy, (5-phenyl-2-oxo-1,3-dioxolen-4-yl)methoxy, optionally substituted amino or nitro; Y is --NH-- or oxygen or sulfur; n is 1 to 5; and tautomers and salts of said compounds of formula (I), have the ability to inhibit blood platelet aggregation, and can thus be used for treatment and prophylaxis of thrombosis and embolisms.
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- Mass spectrometric investigations on phenylacetic acid derivatives, IV: Loss of ortho-substituents from ionized phenyl-2-propanones upon electron impact
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In the gas phase, the phenyl-2-propanone molecules 2a-4a lose upon electron impact chloro-, bromo-, and iodo-radicals specifically at the orthopOsition of the phenyl group giving rise to strong (M-Hal.)+-ions (70/12 eV; 1st and 2nd FFR) of identical structure as confirmed by their MIKE-CAD-spectra. The daughter ions at m/z 133 from o-chlorophenyl-2-propanone (2a) and 2,2-dimethyl-2,3-dihydro[b]furane (11) are structurally similar but not identical (similarity index 99.8). The collisionally activated (2nd FFR) (M-Br.)+-ions from o-bromophenyl-2-propanone (3a) and 1-bromo-1-phenyl-2-propanone (12) produce virtually congruent spectra. The most impOrtant subsequent fragmentation of the (M-Hal-)+-ions from 2a-4a is the loss of CO which incorporates the C-atom of the carbonyl group exclusively (13C labelling). Mechanistic aspects of the fragmentation sequences are discussed (Figs. 5 and 8).
- Striegel,Mayer,Wiegrebe,Schlunegger,Siegrist,Aebi
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p. 751 - 760
(2007/10/02)
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- Preparation of benzyl ketones
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Benzyl ketones of the general formula I STR1 where R1 is C1 -C8 -alkyl which is unsubstituted or substituted by cycloalkyl or aryl and R2 and R3 are each halogen, C1 -C4 -alkyl, hydroxyl, C1 -C4 -alkoxy or C2 -C4 -methylenedioxy, are prepared by a process in which a glycol monoether of the general formula II STR2 where R1, R2 and R3 have the abovementioned meanings and R4 is C1 -C8 -alkyl, is converted in the presence of silica, a phosphate or a zeolite at from 50° to 500° C. and under from 0.01 to 50 bar.
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- Reactions of O,O-Diprotonated Nitro Olefins with Benzenes. Formations of Phenylacetones, 4H-1,2-Benzoxazines and Biarylacetone Oximes
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O,O-Diprotonated nitro olefins undergo three alternative electrophilic reactions which yield α-phenylacetones, 4H-1,2-benzoxazines and biphenylacetone oximes depending on the reaction conditions (temperature and time) and aromatic substrates.Although these reactions are seemingly divergent, a common intermediate of a phenylated protonated aci-nitro species, derived from the dication, is postulated to be involved in the reactions.Furthermore, the formation of benzoxazines and biphenylacetone oximes can be interpreted in terms of participation of novel chemical species with phenylethylene dication character derived from the common intermediate.
- Ohwada, Tomohiko,Okabe, Kazuaki,Ohta, Toshiharu,Shudo, Koichi
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p. 7539 - 7555
(2007/10/02)
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- Novel Electrophilic Species Equivalent to α-Keto Cations. Reactions of O,O-Diprotonated Nitro Olefins with Benzenes Yield Arylmethyl Ketones
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The N,N-dihydroxyiminium carbenium ions formed by O,O-diprotonation of nitro olefins in a strong acid, trifluoromethanesulfonic acid (TFSA), are discrete and novel dipositively charged species.The dications formed from α-substitited nitroethylenes are reactive electrophiles to give α-arylated ketones in high yields.This constitutes a versatile synthetic method for the preparation of α-arylated ketones, which are difficult to synthesize by the conventional Friedel-Crafts reactions.
- Okabe, Kazuaki,Ohwada, Tomohiko,Ohta, Toshiharu,Shudo, Koichi
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p. 733 - 734
(2007/10/02)
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- Studies on nucleophilic substitution reactions with cyclopentadienyliron complexes of some chloroarenes and nitorarenes and syntheses of substituted arenes by demetallation of the substitution products
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Nucleophilic substitution reactions with the cyclopentadienyliron (CpFe) complex of m- or p-dichlorobenzene with carbanion nucleophiles derived from ethyl acetoacetate (EAA), dibenzoylmethane (DBM) or diacetylmethane (DAM) were found to give only monosubstitution as previously observed for the CpFe complex of o-dichlorobenzene.Reaction of the CpFe complex of 2,6-dimethylchlorobenzene (XIVa) or 2,6-dimethylnitorbenzene (XIVb) with nucleophiles derived from ammonia, dimethylamine, n-butylamine, pyrrolidine, ethanol, phenol, o-thiocresol and EAA all gave SNAr products, without significant steric hindrance.However, no reaction was observed in the treatment of XIVa or XIVb with DBM, suggesting that only with a bulky nucleophile such as that derived from DBM were steric hindrance effects sufficiently large to prevent an SNAr reaction with XIVa or XIVb.Pyrolytic sublimation of the various SNAr products was found to cause decomposition in some cases, but in most instances, demetallation took place giving rise to substituted arenes.New substituted arenes prepared in this way in the present work included RC6H4CH(COC6H5)2, with R = p-CH3, o-Cl, m-Cl or p-Cl, and 2,6-(CH3)2C6H3Y, with Y = CH3(CH2)3NH, C2H5O or o-CH3C6H4S.
- Abd-El-Aziz, A.S.,Lee, C. C.,Piorko, A.,Sutherland, R. G.
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- Yanovsky Reaction of η6-Arene-η5-cyclopentadienyliron Cations with Carbanions derived from Ketones. Regiospecific Attack ortho to Electron Withdrawing Functions
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η6-Arene-η5-cyclopentadienyliron salts containing electron withdrawing groups such as nitro, halogeno, benzoyl, cyano, and sulphonyl on the arene ring react with carbanions to give electroneutral adducts of the Yanovsky type; these a
- Sutherland, Ronald G.,Chowdhury, Ratan L.,Piorko, Adam,Lee, Choi Chuck
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p. 1296 - 1297
(2007/10/02)
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- Aromatic Acetonylation Promoted by Manganese(III) and Cerium(IV) Salts
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Treatment of aromatic hydrocarbons with acetone and manganese(III) acetate gave rise to arylacetones in yields ranging from 25 percent with chlorobenzene to 74 percent with anisole.Cerium(IV) salts were also successfully used as promoters but gave lower yields.The reactions were relatively free of side products except with toluene.Isomer distributions, relative rates, and partial rate factors were determined for acetonylation of anisole, toluene, chlorobenzene, and fluorobenzene.A Hammett plot of the log of the partial rate factors for the manganese(III) system vs. ?-constants gave a slope, ρ, of -2.4 +/- 0.3.An isotope effect kH/kD = 3.8 was observed for the manganese(III)-promoted reaction with acetone-d6, indicating rate-determining proton loss from acetone.The overall mechanism involves formation and attack of acetonyl radicals onto the aromatic hydrocarbon followed by subsequent oxidative deprotonation of the resulting ?-radical complex.The acetonyl radical exhibits appreciable electron-deficient character in its substitution behavior with aromatic hydrocarbons.
- Kurz, Michael E.,Baru, Vijayalakshmi,Nguyen, P-Nhi
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p. 1603 - 1607
(2007/10/02)
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- ACETONYLATION AROMATIQUE HOMOLYTIQUE
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Treatment of monosubstituted benzene derivatives with acetone and manganese(III) acetate in acetic acid gave rise to products of homolytic aromatic substitution in fairly good yields and high purity except for toluene.Isomer distribution, relative rates and partial rate factors were determeined for toluene, anisole, chlorobenzene, bromobenzene and benzonitrile.A Hammet plot of the logarithm of the partial rate factors for meta and para positions vs. ?-constants gave a slope ρ of -1.74 +/- 0.40 (confidence interval at the level 95percent).When using ?+-constants the slope becomes ρ+ = -1.25 +/- 0.36.The negative velues of ρ and ρ+ indicated that the acetonyl radical has an appreciable electrophilic character.
- Gardrat, C.
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p. 897 - 902
(2007/10/02)
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- Arylation and 1-Alkenylation on α-Position of Ketones via Tributyltin Enolates Catalyzed by Palladium Complex
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The reaction of tributyltin enolates, prepared from tributyltin methoxide and enol acetates in situ, with aryl and 1-alkenyl bromides in the presence of dichlorobis(tri-o-tolylphosphine)palladium was found to give α-aryl and α-(1-alkenyl) ketones, respectively, in good yields with essentially complete retention of the enol acetate regiochemistry.
- Kosugi, Masanori,Hagiwara, Isao,Sumiya, Takao,Migita, Toshihiko
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p. 241 - 246
(2007/10/02)
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- The Allopolarization Principle and its Applications, IV. Substituent Effects in the Methylation of Enolate Anions
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The ratio of O- and C-methylated products in the reaction of the sodium salts of acetophenones 1, propiophenones 3, phenylacetones 5, β-dicarbonyl compounds 12, α-cyanocarbonyl compounds 13, acetaldehyde, propionaldehyde, and diethylketone with dimethyl sulfate, methyl iodide, and trimethyl phosphate in HMPTA has been determined with regard to the effect of substituents.In some cases the influence of solvents, concentration and temperature has also been studied.
- Gompper, Rudolf,Vogt, Hans-Hubert
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p. 2866 - 2883
(2007/10/02)
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