- PdII-Catalyzed Regio- and Enantioselective Oxidative C?H/C?H Cross-Coupling Reaction between Ferrocenes and Azoles
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Asymmetric C?H bond functionalization reaction is one of the most efficient and straightforward methods for the synthesis of optically active molecules. Herein we disclose an asymmetric C?H/C?H cross-coupling reaction of ferrocenes with azoles such as oxazoles and thiazoles. Palladium(II)/monoprotected amino acid (MPAA) catalytic system which exhibits excellent reactivity and regioselectivity for oxazoles and thiazoles. This method offers a powerful strategy for constructing planar chiral ferrocenes. Mechanistic studies suggest that the C?H bond cleavage of azoles is likely proceeding through a SEAr process and may not be a turnover limiting step.
- Cai, Zhong-Jian,Liu, Chen-Xu,Gu, Qing,Zheng, Chao,You, Shu-Li
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supporting information
p. 2149 - 2153
(2019/01/24)
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- Widely Exploited, Yet Unreported: Regiocontrolled Synthesis and the Suzuki–Miyaura Reactions of Bromooxazole Building Blocks
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An approach to synthesis of 2-, 4-, and 5-bromooxazoles is described. The method was optimized, and its scope was extended to all three isomeric parents, as well as various alkyl- and aryl-substituted bromooxazoles. It was found that direct regiocontrolled lithiation followed by reaction with electrophilic bromine source was common for all substrates and led exclusively to the target substituted 2-, 4- and 5-bromooxazoles on multigram scale. The utility of the multipurpose building blocks obtained in this work was demonstrated in the Suzuki–Miyaura cross-coupling reaction under parallel synthesis conditions.
- Solomin, Vitalii V.,Radchenko, Dmytro S.,Slobodyanyuk, Evgeniy Y.,Geraschenko, Oleksandr V.,Vashchenko, Bohdan V.,Grygorenko, Oleksandr O.
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p. 2884 - 2898
(2019/03/07)
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- Synthesis of Triarylpyridines in Thiopeptide Antibiotics by Using a C-H Arylation/Ring-Transformation Strategy
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We have described a C-H arylation/ring-transformation strategy for the synthesis of triarylpyridines, which form the core structure of thiopeptide antibiotics. This synthetic method readily gave 2,3,6-triarylpyridines in a regioselective manner by a two-p
- Amaike, Kazuma,Itami, Kenichiro,Yamaguchi, Junichiro
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supporting information
p. 4384 - 4388
(2016/03/22)
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- Facile structural elucidation of imidazoles and oxazoles based on NMR spectroscopy and quantum mechanical calculations
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The reaction of 1,2,3-tricarbonyl derivatives with hexamethylenetetramine and ammonium acetate in acetic acid provides an unambiguous approach to the synthesis of imidazoles, whereas the Bredereck reaction of α-haloketones in formamide, yields both imidazoles and oxazoles. Herein we describe a facile methodology for distinguishing between these heterocyclic compounds based on a combination of NMR spectroscopy and quantum mechanical calculations. In the NMR data the oxazole C-2 has a chemical shift of ca. 150 ppm whereas in the imidazoles it is found at ca. 135 ppm, with a 1JC-H of ca. 250 Hz for the oxazoles and ca. 210 Hz for the imidazoles. 1JC-H values can be easily obtained from a gated-decoupled 13C spectrum, and even more trivially, from the separation of the H-2 13C satellites in the 1H spectra. Additionally, the computed NMR data, obtained from density functional theory, are found to be in good agreement with the experimental data and serve as valuable tools in identifying the products of the Bredereck reaction.
- Weitman, Michal,Lerman, Lena,Cohen, Shmuel,Nudelman, Abraham,Major, Dan T.,Gottlieb, Hugo E.
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scheme or table
p. 1465 - 1471
(2010/04/04)
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- Synthesis and biological evaluation of 5-substituted and 4,5-disubstituted-2-arylamino oxazole TRPV1 antagonists
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The synthesis and structure-activity relationships of a series of 5-monosubstituted and 4,5-disubstituted 2-arylaminooxazoles as novel antagonists of the transient receptor potential vanilloid 1 (TRPV1) receptor are described. The 7-hydroxy group of the t
- Perner, Richard J.,Koenig, John R.,Didomenico, Stanley,Gomtsyan, Arthur,Schmidt, Robert G.,Lee, Chih-Hung,Hsu, Margaret C.,McDonald, Heath A.,Gauvin, Donna M.,Joshi, Shailen,Turner, Teresa M.,Reilly, Regina M.,Kym, Philip R.,Kort, Michael E.
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scheme or table
p. 4821 - 4829
(2010/08/06)
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- Chemical Compounds
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This invention relates to non-steroidal compounds that are modulators of androgen, glucocorticoid, mineralocorticoid, and progesterone receptors, and also to the methods for the making and use of such compounds.
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Page/Page column 54
(2009/07/17)
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- Synthesis of azirines containing aldehyde functionality and their utilization as synthetic tools for five membered oxazoles and isoxazoles
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(Chemical Equation Presented) A simple and useful procedure for the synthesis of azirines containing aldehyde functionality from open chain bromo/chloro-aldehydes at room temperature is reported. The scope of the ring expansion reaction of a number of 3-s
- Brahma, Sulagna,Ray, Jayanta K.
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p. 311 - 317
(2008/09/20)
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- 2- [ (2-SUBSTITUTED) -IND0LIZIN-3-YL] -2-OXO-ACETAMIDE DERIVATIVES AS ANTIFUNGAL AGENTS
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The invention provides compounds of formula (I), and pharmaceutically acceptable salts thereof wherein: Rl, R2, R3, R4, R5, R6, R7, X and X1 are as defined herein. These compounds are useful in the manufacture of medicaments for use in the prevention or treatment of a fungal disease. Compounds of formula (I), and agriculturally acceptable salts thereof, may also be used as agricultural fungicides.
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Page/Page column 113
(2008/12/05)
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- A domino copper-catalyzed C-N and C-O cross-coupling for the conversion of primary amides into oxazoles
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A variety of oxazoles can efficiently be prepared, in a single step and in good yield, from primary amides and 1,2-dihaloalkenes using copper-catalysis. This new method allows the regioselective formation of a range of substituted oxazoles. The required 1,2-dihaloalkenes can prepared by simple treatment of alkynes with elemental bromine or iodine. Georg Thieme Verlag Stuttgart.
- Schuh, Kerstin,Glorius, Frank
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p. 2297 - 2306
(2008/02/13)
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- ARYLOXYETHYLAMINE COMPOUNDS SUITABLE FOR TREATING DISORDERS THAT RESPOND TO MODULATION OF THE DOPAMINE D3 RECEPTOR
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The present invention relates to aryloxyethylamine compounds of the formula (I) and the physiologically tolerated acid addition salts thereof. The variables have the meanings given in the claims and the description. The invention also relates to the use o
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Page/Page column 126
(2008/06/13)
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- Discovering novel chemical inhibitors of human cyclophilin A: Virtual screening, synthesis, and bioassay
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Cyclophilin A (CypA) is a member of cyclophilins, a family of the highly homologous peptidyl prolyl cis-trans isomerases (PPIases), which can bind to cyclosporin A (CsA). CypA plays critical roles in various biological processes, including protein folding, assembly, transportation, regulation of neuron growth, and HIV replication. The discovery of CypA inhibitor is now of a great special interest in the treatment of immunological disorders. In this study, a series of novel small molecular CypA inhibitors have been discovered by using structure-based virtual screening in conjunction with chemical synthesis and bioassay. The SPECS_1 database containing 85,000 small molecular compounds was searched by virtual screening against the crystal structure of human CypA. After SPR-based binding affinity assay, 15 compounds were found to show binding affinities to CypA at submicro-molar or micro-molar level (compounds 1-15). Seven compounds were selected as the starting point for the further structure modification in considering binding activity, synthesis difficulty, and structure similarity. We thus synthesized 40 new small molecular compounds (1-6, 15, 16a-q, 17a-d, and 18a-l), and four of which (compounds 16b, 16h, 16k, and 18g) showed high CypA PPIase inhibition activities with IC50s of 2.5-6.2 μM. Pharmacological assay indicated that these four compounds demonstrated somewhat inhibition activities against the proliferation of spleen cells.
- Li, Jian,Chen, Jing,Gui, Chunshan,Zhang, Li,Qin, Yu,Xu, Qiang,Zhang, Jian,Liu, Hong,Shen, Xu,Jiang, Hualiang
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p. 2209 - 2224
(2007/10/03)
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- Photochemistry of 4- and 5- phenyl substituted isoxazoles
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5-Phenylisoxazole (4) and 4-phenylisoxazole (22) underwent phototransposition to 5-phenyloxazole (5) and 4-phenyloxazole (24) respectively. Labeling with deuterium or methyl confirmed that these phototrans-positions occurred via the P4 pathway which involves only interchange of the N2 and C3 ring position. Thus, 4-deuterio-5-phenylisoxazole (4-4d), 4-methyl-5-phenylisoxazole (10), and 5-methyl-4-phenylisoxazole (23) phototransposed to 4-deuterio-5-phenyloxazole (5-4d), 4-methyl-5-phenyloxazole (11), and 5-methyl-4-phenyloxazole (25) respectively. In addition to phototransposition, isoxazoles 4, 10, and 23 also underwent photo-ring cleavage to yield benzoylacetonitrile (9), α-benzoylpropionitrile (15), and aceto-α-phenyl-acetonitrile (26) respectively. Irradiation of 5-phenyl-3-(trifluoromethyl)isoxazole (16) in acetonitrile led to 5-phenyl-2-(trifluoromethyl)oxazole (17), the P4 phototransposition product. Irradiation of 16 in methanol led to a substantial decrease in the yield of 17 and to the formation of a mixture of (E) and (Z)-2-methoxy-2- (trifluoromethyl)-3-benzoylaziridines 18a and 18b.
- Pavlik, James W.,St. Martin, Heather,Lambert, Karen A.,Lowell, Jennifer A.,Tsefrikas, Vikki M.,Eddins, Cheryl K.,Kebede, Naod
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p. 273 - 281
(2007/10/03)
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- Discovery of a novel class of selective non-peptide antagonists for the human neurokinin-3 receptor. 1. Identification of the 4-quinolinecarboxamide framework
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A novel class of potent and selective non-peptide neurokinin-3 (NK-3) receptor antagonists, featuring the 4-quinolinecarboxamide framework, has been designed based upon chemically diverse NK-1 receptor antagonists. The novel compounds 33-76, prompted by chemical modifications of the prototype 4, have been characterized by binding analysis using a membrane preparation of chinese hamster ovary (CHO) cells expressing the human neurokinin-3 receptors (hNK-3-CHO), and clear structure-activity relationships (SARs) have been established. From SARs, (R)-N-[α-(methoxycarbonyl)benzyl]-2- phenylquinoline-4-carboxamide (65, SB 218795, hNK-3-CHO binding K(i) = 13 nM) emerged as one of the most potent compounds of this novel class. Selectivity studies versus the other neurokinin receptors (hNK-2-CHO and hNK-1-CHO) revealed that 65 is about 90-fold selective for hNK-3 versus hNK-2 receptors (hNK-2-CHO binding K(i) = 1221 nM) and over 7000-fold selective versus hNK-1 receptors (hNK-1-CHO binding K(i) = >100 μM). In vitro functional studies in rabbit isolated iris sphincter muscle preparation demonstrated that 65 is a competitive antagonist of the contractile response induced by the potent and selective NK-3 receptor agonist senktide with a K(b) = 43 nM. Overall, the data indicate that 65 is a potent and selective hNK-3 receptor antagonist and a useful lead for further chemical optimization.
- Giardina, Giuseppe A. M.,Sarau, Henry M.,Farina, Carlo,Medhurst, Andrew D.,Grugni, Mario,Raveglia, Luca F.,Schmidt, Dulcie B.,Rigolio, Roberto,Luttmann, Mark,Vecchietti, Vittorio,Hay, Douglas W. P.
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p. 1794 - 1807
(2007/10/03)
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- 3 and 5 alkyl and phenyl 4-(hydroxy or acyloxy)-alkyl substituted 2(5H)-furanones as anti-inflammatory agents
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Novel anti-inflammatory furanone compounds have the following formula: STR1 where R1 independently is H, or alkyl of 1 to 9 carbons and n is an integer having the values of 1 or 2, and where when n is 1 the R1 group is attached to th
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- Benzyne-Oxazole Cycloadducts: Isolation and Retro-Diels-Alder Reactions
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A literature procedure for generating benzyne from 1-aminobenzotriazole and lead tetraacetate was modified by the use of two syringe pumps to effect simultaneous addition through opposing ports of a three-neck flask.Applied to the reaction of benzyne with 4-phenyloxazole at 0 deg C, this modification resulted in essentially quantitative formation of cycloadduct.Retro-Diels-Alder expulsion of benzonitrile with concurrent formation of isobenzofuran occurred when the adduct was heated.The sequence constitutes a useful method of preparation of isobenzofuran, which may be utilized in situ or isolated as a solution for subsequent application.Benzyne cycloadducts were also prepared from 4-(4-nitrophenyl)- and 4-(4-methoxyphenyl)oxazoles, in order to assess the effect of remote substituents on the retro-Diels-Alder reaction.First-order rate constants were determined at three temperatures in the range of 40-70 deg C.The order of reactivity was p-NO2 > p-H > p-OMe; the substituent effects were small, with a factor 4 separating the p-NO2 from p-OMe rate.All three substrates exhibited small ΔS(excit.) values.Expulsion of the nitrile is believed to occur as a concerted reaction with little charge development.The modified benzyne procedure was also applied to 2,5-diphenyloxazole, at 0 and -78 deg C.Oxazole was recovered (59percent and 43percent at the higher and lower temperature, respectively).No bis(benzyne) adduct was formed, showing that 1,3-diphenylisobenzofuran is not generated during the course of the reaction.The 1:1 benzyne-diphenyloxazole cycloadduct is not observed in the crude product of the0 deg C reaction, but an absorption at 6.09 ppm in the NMR spectrum of crude product from the -78 deg C reaction is attributed to this material.The latter crude product on standing at room temperature forms the isobenzofuran.Both reaction mixtures form 1,3-diphenylisobenzofuran by another mechanism involving a second intermediate.This more polar intermediate, which appears to be the major product at 0 deg C, slowly gives 1,3-diphenylisobenzofuran.The overall more efficient cycloaddition at - 78 deg C is attributed to entropy effects, which tend to favor Diels-Alder over other second-order reactions as the temperature is lowered.
- Whitney, Scott E.,Winters, Michael,Rickborn, Bruce
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p. 929 - 935
(2007/10/02)
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- Isolation of a 1:1 Oxazole-Benzyne Cycloadduct: An Improved Method for Generating Benzyne and a New Approach to Isobenzofuran
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A dual syringe pump addition procedure for benzyne generation from 1-aminobenzotriazole with Pb(OAc)4 is applied to 4-phenyloxazole at 0 deg C, to give the isolable 1:1 benzyne/oxazole Diels-Alder adduct in essentially quantitative yield; mild solution th
- Whitney, Scott E.,Rickborn, Bruce
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p. 5595 - 5596
(2007/10/02)
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- Photoreactions of Benzonitrile with Cyclic Enol Ethers
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Upon irradiation cyclic enol ethers such as 1-methoxy-cyclopentene (4) mainly add across the cyano group of benzonitrile (1) under formation of 2-azabutadienes of an imidoester type.This is in agreement with the so-called ΔG-correlation which was reported
- Mattay, Jochen,Runsink, Jan,Heckendorn, Roland,Winkler, Tammo
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p. 5781 - 5790
(2007/10/02)
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