- Copper-Catalyzed Enantioconvergent Cross-Coupling of Racemic Alkyl Bromides with Azole C(sp2)?H Bonds
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The development of enantioconvergent cross-coupling of racemic alkyl halides directly with heteroarene C(sp2)?H bonds has been impeded by the use of a base at elevated temperature that leads to racemization. We herein report a copper(I)/cinchona-alkaloid-derived N,N,P-ligand catalytic system that enables oxidative addition with racemic alkyl bromides under mild conditions. Thus, coupling with azole C(sp2)?H bonds has been achieved in high enantioselectivity, affording a number of potentially useful α-chiral alkylated azoles, such as 1,3,4-oxadiazoles, oxazoles, and benzo[d]oxazoles as well as 1,3,4-triazoles, for drug discovery. Mechanistic experiments indicated facile deprotonation of an azole C(sp2)?H bond and the involvement of alkyl radical species under the reaction conditions.
- Chang, Xiao-Yong,Chen, Ji-Jun,Gu, Qiang-Shuai,Jiang, Sheng-Peng,Li, Zhong-Liang,Liu, Lin,Liu, Xiao-Dong,Liu, Xin-Yuan,Su, Xiao-Long,Wang, Fu-Li,Yang, Chang-Jiang,Ye, Liu
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supporting information
p. 380 - 384
(2020/10/30)
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- Efficient Transfer Hydrogenation of Ketones using Methanol as Liquid Organic Hydrogen Carrier
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Herein, we demonstrate an efficient protocol for transfer hydrogenation of ketones using methanol as practical and useful liquid organic hydrogen carrier (LOHC) under Ir(III) catalysis. Various ketones, including electron-rich/electron-poor aromatic ketones, heteroaromatic and aliphatic ketones, have been efficiently reduced into their corresponding alcohols. Chemoselective reduction of ketones was established in the presence of various other reducible functional groups under mild conditions.
- Garg, Nidhi,Paira, Soumen,Sundararaju, Basker
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p. 3472 - 3476
(2020/05/29)
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- Method for synthesizing alkyne through catalytic asymmetric cross coupling (by machine translation)
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The invention belongs to the field of, asymmetric synthesis, and discloses a method for catalyzing asymmetric cross- coupling to synthesize: an alkyne, and the L method comprises, the following steps, of A: preparing B a cuprous, salt and C a: ligand; preparing a catalyst; adding a base; reacting the compound with the compound with the compound; and reacting the compound with the compound. Of these, one of them, X is selected from the group consisting of, R halogens. 1 Optionally substituted heteroarylsulfonylcyanamide groups selected from the, group consisting, of optionally substituted, phenyl groups In-flight vehicle, R6 Trialkyl silyl groups or alkyl radicals, R2 Cycloalkyl radicals optionally substituted with an, optionally substituted alkyl, (CH radical2 )n R4 Multi,layer chain, n=0-10,R saw blade4 A group selected, from, the group consisting of phenyl, alkenyl, aralkynyls, noonyloxy,and, noonylsulfonylsulfonylsulfonylsulfonylsulfonylsulfonylsulfonylsulfonylsulfonylsulphonylsulphonylsulphonylsulphonylsulphonylsulphonylsulphonylsulphonylsulphonylsulphonylphenyl disiloxy-radicals. R3 A ligand, selected from hydrogen or any of the functional groups, is selected from the group consisting of, hydrogen and any L other functional group. The method, R disclosed by the, A invention has the, advantages of good catalytic, R ’ effect, wide application range. and high catalytic efficiency, and the, method disclosed by the, invention has the. advantages of good catalytic effect, wide application range and high catalytic efficiency. (by machine translation)
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Paragraph 0205; 0291-0296
(2020/01/12)
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- DMF Dimethyl Acetal as Carbon Source for α-Methylation of Ketones: A Hydrogenation-Hydrogenolysis Strategy of Enaminones
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A novel heterogeneous catalytic hydrogenation-hydrogenolysis strategy has been developed for the α-methylation of ketones via enaminones using DMF dimethyl acetal as carbon source. This strategy provides a very convenient route to α-methylated ketones using a variety of ketones without any base or oxidant. (Chemical Equation Presented).
- Borah, Ashwini,Goswami, Limi,Neog, Kashmiri,Gogoi, Pranjal
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p. 4722 - 4728
(2015/05/13)
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- Enantioselective addition of diethylzinc to aromatic aldehydes catalyzed by C2-symmetric chiral diols
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Optically pure C2-symmetric diols have been synthesized with moderate yields in a straightforward manner, and are used as catalysts in the enantioselective alkylation of aromatic aldehydes with diethylzinc. The addition of diethylzinc to benzal
- G?k, Ya?ar,Keke?, Levent
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p. 2727 - 2729
(2014/05/06)
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- Straightforward access to chiral diol bidentate ligands: Their efficient enantioselective induction in the addition of diethylzinc to aromatic aldehydes
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Enantiopure C2-symmetric diol bidentate ligands have been synthesized in a straightforward manner through a three-step reaction with good yields. The synthesized C2-symmetric diol bidentate ligands were used in the addition of diethylzinc to various aromatic aldehydes, a general catalytic benchmark reaction, in order to assess their enantioselective induction properties. The enantioselective addition of diethylzinc to 1-naphthaldehyde and 3-chlorobenzaldehyde was achieved with an enantiomeric excess (ee) of up to 98%. All synthesized ligands were also evaluated in the addition of diethyzinc to aromatic aldehydes including an extra metal such as Ti(IV) (up to 99% ee).
- G?k, Yaar,Külolu, Soner,G?k, Halil Zeki,Kekec, Levent
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p. 835 - 838
(2015/02/19)
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- Straightforward access to chiral diol bidentate ligands: Their efficient enantioselective induction in the addition of diethylzinc to aromatic aldehydes
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Enantiopure C2-symmetric diol bidentate ligands have been synthesized in a straightforward manner through a three-step reaction with good yields. The synthesized C2-symmetric diol bidentate ligands were used in the addition of diethylzinc to various aromatic aldehydes, a general catalytic benchmark reaction, in order to assess their enantioselective induction properties. The enantioselective addition of diethylzinc to 1-naphthaldehyde and 3-chlorobenzaldehyde was achieved with an enantiomeric excess (ee) of up to 98%. All synthesized ligands were also evaluated in the addition of diethyzinc to aromatic aldehydes including an extra metal such as Ti(IV) (up to 99% ee).
- G?k, Ya?ar,Küloglu, Soner,G?k, Halil Zeki,Kekec?, Levent
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p. 835 - 838
(2015/04/16)
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- PROCESS FOR THE PREPARATION OF L-PHENYL-3-DIMETHYLAMINOPROPANE DERIVATIVES
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The present invention provides a process for the preparation of 1-phenyl-3-dimethylaminopropane derivatives of formula I, and its pharmaceutically acceptable salts thereof from intermediate of formula II, wherein R1 can be selected from -OR2, halo, -CH2OR2, -SR2, SOR2, SO2R2, -SO3H, -NO2, -NR2R2', - CONR2R2 ', carboxylic esters, sulfonate esters or phosphate esters and the like; R ' can be selected from hydrogen, alkyl, aryl, aralkyl, alkaryl, heteroaryl, and the like; or OR ' can be selected from -NR2R2 '; or R2 and R2 ' can be same or different and can be selected from hydrogen, alkyl, aryl, aralkyl, heteroaryl,-OR3, - COR3, -PO3(R3R4) wherein R3 and R4 can be same or different and can be selected from alkyl, aryl, aralkyl, heteroaryl and the like.
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Page/Page column 37
(2011/08/21)
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- NOVEL COMPOUNDS
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The present invention relates to novel NADPH oxidase II inhibitors and their use in the treatment of diseases mediated by the NADPH oxidase II enzyme.
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Page/Page column 26
(2011/07/07)
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- N, N′-dioxide-Cu(OTf)2 complex catalyzed highly enantioselective amination reaction of N-acetyl enamide
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The N,N′-dioxide-Cu(OTf)2 complexes were applied in the asymmetric amination reaction of N-acetyl enamides with dialkyl azodicarboxylate, giving the corresponding products in good yields with high enantioselectivities (up to 91% ee). Precursors of vicinal diamine were readily obtained with excellent diastereoselectivities (>95:5) by NaBH4 reduction.
- Chang, Lu,Kuang, Yulong,Qin, Bo,Zhou, Xin,Liu, Xiaohua,Lin, Lili,Feng, Xiaoming
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supporting information; experimental part
p. 2214 - 2217
(2010/08/06)
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- Alternative method for alkylation of arylpolyhalomethanes with trialkylborane in the presence of magnesium
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Reduction of benzal halide derivatives and α,α,α,-trichloromethylbenzene by magnesium powder in DMAc affords α-halocarbanions which then react with triethylborane to give alkylated products. After oxidation with H2O2-NaOH, secondary
- Condon, Sylvie,Nédélec, Jean-Yves
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supporting information; experimental part
p. 32 - 35
(2010/09/18)
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- Ruthenium-catalyzed redox isomerization/transfer hydrogenation in organic and aqueous media: A one-pot tandem process for the reduction of allylic alcohols
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The hexamethylbenzene-ruthenium(ii) dimer [{RuCl(μ-Cl) (η6-C6Me6)}2] 1 and the mononuclear bis(allyl)-ruthenium(iv) complex [RuCl2(η 3:η2:η3-C12H 18)]2, associated with base and a hydrogen donor, were found to be active catalysts for the selective reduction of the CC bond of allylic alcohols both in organic and aqueous media. The process, which proceeds in a one-pot manner, involves a sequence of two independent reactions: (i) the initial redox-isomerization of the allylic alcohol, and (ii) subsequent transfer hydrogenation of the resulting carbonyl compound. The highly efficient transformation reported herein represents, not only an illustrative example of auto-tandem catalysis, but also an appealing alternative to the classical transition-metal catalyzed CC hydrogenations of allylic alcohols. The process has been successfully applied to aromatic as well as aliphatic substrates affording the corresponding saturated alcohols in 45-100% yields after 1.5-24 h. The best performances were reached using (i) 1-5 mol% of 1 or 2, 2-10 mol% of Cs2CO3, and propan-2-ol or (ii) 1-5 mol% of 1 or 2, 10-15 equivalents of NaO2CH, and water. The catalytic efficiency is strongly related to the structure of the allylic alcohol employed. Thus, in propan-2-ol, the reaction rate essentially depends on the steric requirement around the CC bond, therefore decreasing with the increasing number of substituents. On other hand, in water the transformation is favoured for primary allylic alcohols vs. secondary ones.
- Cadierno, Victorio,Crochet, Pascale,Francos, Javier,Garcia-Garrido, Sergio E.,Gimeno, Jose,Nebra, Noel
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scheme or table
p. 1992 - 2000
(2010/06/19)
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- Ruthenium-catalyzed reduction of allylic alcohols: An efficient isomerization/transfer hydrogenation tandem process
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A simple and highly efficient method for the selective reduction of the C=C bond in allylic alcohols has been developed using the ruthenium(ii) catalyst [{RuCl(μ-Cl)(η6-C6Me6)}2]. The Royal Society of Chemistry.
- Cadierno, Victorio,Francos, Javier,Gimeno, Jose,Nebra, Noel
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p. 2536 - 2538
(2008/02/11)
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- Methoxy-substituted stilbenes, styrenes, and 1-arylpropenes: Photophysical properties and photoadditions of alcohols
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The photochemistry of trans-stilbene and four methoxy-substituted stilbene derivatives has been investigated in a variety of solvents. The fluorescence of all five trans isomers was quenched by 2,2,2-trifluoroethanol (TFE). Upon irradiation of the five substrates in TFE, the products derived from photoaddition of the solvent were detected. Nuclear magnetic resonance spectroscopy of the products formed by irradiation in TFE-OD indicated that the proton and nucleophile are attached to two adjacent atoms of the original alkene double bond. Irradiation of the corresponding methoxy-substituted styrenes and trans-1-arylpropenes in TFE produced the analogous solvent adducts. The photoaddition of TFE proceeded with the general order of reactivity: styre > trans-1-arylpropenes > trans-stilbenes. Transient carbocation intermediates were observed following laser flash photolysis of the stilbenes in 1,1,1,3,3,3-hexafluoro-2-propanol (HFIP). The results are consistent with a mechanism that involves photoprotonation of the substrates by TFE or HFIP, followed by nucleophilic trapping of short-lived carbocation intermediates. Compared to the other stilbene derivatives, trans-3,5-dimethoxystilbene displayed a large quantum yield of fluorescence and a low quantum yield of trans-cis isomerization in polar organic solvents. The unique photophysical properties of trans-3,5-dimethoxystilbene are attributed to formation of a highly polarized charge-transfer excited state (μe = 13.2 D).
- Roberts, Jeffrey C.,Pincock, James A.
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p. 1480 - 1492
(2007/10/03)
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- Asymmetric activation of chiral alkoxyzinc catalysts by chiral nitrogen activators for dialkylzinc addition to aldehydes: Super high-throughput screening of combinatorial libraries of chiral ligands and activators by HPLC-CD/UV and HPLC-OR/RIU systems
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Asymmetric catalysts, prepared by chiral ligand exchange or chiral modification, can evolve further into highly activated catalysts through engineering with chiral activators. Two new methodologies for "super high-throughput screening" (SHTS) of chiral ligands and activators have been developed as a combination of HPLC-CD/UV (CD/ UV = circular dichroism/ultraviolet spectroscopy) or -OR/RIU (OR/RIU = optical rotation/refractive index unit) with a combinatorial chemistry (CC) factory. With these techniques, the percent ee of the product is determined within minutes without separation of the enantiomeric products by using a nonchiral stationary phase. Therefore, those SHTS techniques combined with our 'asymmetric activation' concept can provide a powerful strategy for finding the best activated chiral catalyst. ? WILEY-VCH Verlag GmbH, 2001.
- Mikami, Koichi,Angelaud, Re?my,Ding, Kuiling,Ishii, Akihiro,Tanaka, Akito,Sawada, Naotaka,Kudo, Kenichi,Senda, Masaaki
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p. 730 - 737
(2007/10/03)
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- Photochemistry of substituted propiophenones: An interesting α-and aryl substituents effect on their photobehaviour
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Photochemistry of different α-substituted and phenyl-substituted propiophenones in methanol is investigated with a view to delineate the substituent effect with a special reference tu their rearrangement to α-arylpropanoic acids, an important class of nonsteroidal antiinflammatory agents. The results thus obtained bringsforth an important element of their reactivityprofile i.e. the α-chloro-substituent in combination with nuclear alkyl substituents (para>meta) favours 1,2-arylmigration leading to the synthetically useful reaction for α-arylpro panoic acids.
- Sonawane, Harikisan R.,Bellur, Nanjundiah S.,Nazeruddin
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p. 11281 - 11294
(2007/10/02)
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- Synthesis and activity of 2-methyl-3-aminopropiophenones as centrally acting muscle relaxants
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Some novel 2-methyl-3-aminopropiophenones were synthesized and their centrally acting muscle relaxant activities were,evaluated for an inhibitory effect on the flexor reflex in rats. The structure-activity relationships are discussed. In this series 2-methyl-3-pyrrolidino-1-(4-trifluoromethylphenyl)-propan-1-one (28) showed significant centrally acting muscle relaxant activity. In addition, the activities of each enantiomer (28-(S) and (R)) were studied along with their acute toxicities. Compound 28-(R) was found to exhibit more potent activity and weaker acute toxicity than 28-(S). Accordingly, compound 28-(R) (NK433) is under development as a novel centrally acting muscle relaxant.
- Shiozawa,Narita,Izumi,Kurashige,Sakitama,Ishikawa
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- Formal Cycloaddition of Benzylic Cations with Alkenes
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The reaction of benzylic cations with styrenes affords dihydro(1H)indenes in good yield via a formal atom cycloadditon.The cations were generated from quinone methides and benzylic alcohols. (E)-Styrenes participate in the reaction with remarkable stereoselectivity affording dihydro(1H)indenes with three stereogenic centers with >40:1 diastereoselectivity.A possible transition state for the reaction is discussed.Less activated alkenes such as dihydropyran and methylcyclohexane afforded cycloadducts in 66percent and 51percent yields, respectively.
- Angle, Steven R.,Arnaiz, Damian O.
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p. 5937 - 5947
(2007/10/02)
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- Quinoline dioic acids and amides
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Compounds having the formula are antagonists of leukotrienes and inhibitors of their biosynthesis. These compounds are useful as anti-asthmatic, anti-allergic, anti-inflammatory, and cytoprotective agents.
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- Reaction of some N-acyl-1-alkylamines with polyphosphoric ester PPE: nuclear magnetic resonance and stereochemistry of reaction products
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Phenylindanes were obtained from the reaction of N-acyl-1-arylalkylamines with polyphosphoric ester (PPE). cis-1-Methyl-3-(3,4-dimethoxyphenyl)-5,6-dimethoxyindane was synthesized to determine which stereoisomer was produced by N-formyl and N-acetyl-1-(3,4-dimethoxyphenyl)ethylamine with PPE.Nuclear magnetic resonance specta (1H and 13C) of several mono-, 1,3-di-, and 1,2,3-tri-substituted indanes were fully analyzed to provide information on steric interactions and conformation of the cyclopentene ring.Possible cyclodimerization pathways are proposed.
- Alesso, Elba N.,Tombari, Dora G.,Iglesias, Graciela Y. Moltrasio,Aguirre, Jose M.
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p. 2568 - 2574
(2007/10/02)
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- Potential Antiestrogens. Synthesis and Evaluation of Mammary Tumor Inhibiting Activity of 1,2-Dialkyl-1,2-bis(3'-hydroxyphenyl)ethanes
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The syntheses of the meso-1,2-dialkyl-1,2-bis(3'-hydroxyphenyl)ethanes and of d,l-3,4-bis(3'-hydroxyphenyl)hexane (21) are described.In vitro these compounds inhibited the estradiol receptor interaction competitively, exhibiting Ka values between 0.20*109 (20) and 0.11*106 M-1 (24).In vivo the meso compounds reduced the estrone-stimulated mouse uterine growth; the most effective compounds were 20, 22, and 23 (53, 50, and 45percent inhibition, respectively).Compounds 20 and 22-24 showed weak estrogenic activity in the mouse uterine weight test and in the vaginal cornification test.Compounds 19 (NSC-297169), 20 (NSC-297170), and 22 (NSC-297171) exhibited a dose-dependent growth inhibition on the MCF-7 human breast tumor cell line (10-6 to 10-9 M).These compounds also showed a marked dose-dependent inhibition on the DMBA-induced, hormone-dependent mammary carcinoma of the Sprague-Dawley rat corresponding to their association constants.
- Hartmann, Rolf W.,Buchborn, Helga,Kranzfelder, Gerhard,Schoenenberger, Helmut,Bogden, Arthur
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p. 1192 - 1197
(2007/10/02)
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- Novel di-(3'-hydroxyphenyl)-alkane compounds, process of preparation and their use in medicine
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Compounds of di-(3'-hydroxyphenyl)-alkanes and their methyl ethers, of the formula STR1 wherein R is alkyl and R' is H or methyl, have activity against hormone-dependent breast carcinoma.
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