- 1,2-Aryl Migration Induced by Amide C?N Bond-Formation: Reaction of Alkyl Aryl Ketones with Primary Amines Towards α,α-Diaryl β,γ-Unsaturated γ-Lactams
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Rearrangement reactions incorporated into cascade reactions play an important role in rapidly increasing molecular complexity from readily available starting materials. Reported here is a Cu-catalyzed cascade reaction of α-(hetero)aryl-substituted alkyl (hetero)aryl ketones with primary amines that incorporates an unusual 1,2-aryl migration induced by amide C?N bond formation to produce a class of structurally novel α,α-diaryl β,γ-unsaturated γ-lactams in generally good-to-excellent yields. This cascade reaction has a broad substrate scope with respect to primary amines, allows a wide spectrum of (hetero)aryl groups to smoothly undergo 1,2-migration, and tolerates electronically diverse α-substituents on the (hetero)aryl ring of the ketones. Mechanistically, this 1,2-aryl migration may stem from the intramolecular amide C?N bond formation which induces nucleophilic migration of the aryl group from the acyl carbon center to the electrophilic carbon center that is conjugated with the resulting iminium moiety.
- Hu, Rong,Tao, Yigao,Zhang, Xiaofeng,Su, Weiping
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p. 8425 - 8430
(2021/03/16)
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- Enantioselective α-Arylation of Ketones via a Novel Cu(I)-Bis(phosphine) Dioxide Catalytic System
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A novel catalytic system based on copper(I) and chiral bis(phosphine) dioxides is described. This allows the arylation of silyl enol ethers to access enolizable α-arylated ketones in good yields and enantiomeric excess up to 95%. Noncyclic ketones are amenable substrates with this method, which complements other approaches based on palladium catalysis. Optimization of the ligand structure is accomplished via rational design driven by correlation analysis. Preliminary mechanistic hypotheses are also evaluated in order to identify the role of chiral bis(phosphine) dioxides.
- Escudero-Casao, Margarita,Licini, Giulia,Orlandi, Manuel
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p. 3289 - 3294
(2021/04/07)
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- Development of bivalent triarylalkene- and cyclofenil-derived dual estrogen receptor antagonists and downregulators
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Up to 80% of mammary carcinoma initially exhibit estrogen-dependent growth, which can be treated by aromatase inhibitors or SERMs/SERDs. To increase the options after failure of the hormonal therapy with these drugs, the search for alternatives with a dif
- Baecker, Daniel,Gaggia, Francesca,Gust, Ronald,Kalchschmid, Christina,Knox, Alexandra,Manzl, Claudia,Schuster, Daniela
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supporting information
(2020/03/13)
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- Highly Stereoselective Synthesis of Tetrasubstituted Acyclic All-Carbon Olefins via Enol Tosylation and Suzuki-Miyaura Coupling
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A highly stereocontrolled synthesis of tetrasubstituted acyclic all-carbon olefins has been developed via a stereoselective enolization and tosylate formation, followed by a palladium-catalyzed Suzuki-Miyaura cross-coupling of the tosylates and pinacol boronic esters in the presence of a Pd(OAc)2/RuPhos catalytic system. Both the enol tosylation and Suzuki-Miyaura coupling reactions tolerate an array of electronically and sterically diverse substituents and generate high yield and stereoselectivity of the olefin products. Judicious choice of substrate and coupling partner provides access to either the E- or Z-olefin with excellent yield and stereochemical fidelity. Olefin isomerization was observed during the Suzuki-Miyaura coupling. However, under the optimized cross-coupling reaction conditions, the isomerization was suppressed to 5% in most cases. Mechanistic probes indicate that the olefin isomerization occurs via an intermediate, possibly a zwitterionic palladium carbenoid species.
- Li, Beryl X.,Le, Diane N.,Mack, Kyle A.,McClory, Andrew,Lim, Ngiap-Kie,Cravillion, Theresa,Savage, Scott,Han, Chong,Collum, David B.,Zhang, Haiming,Gosselin, Francis
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supporting information
p. 10777 - 10783
(2017/08/15)
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- Synthesis of Highly Stereodefined Tetrasubstituted Acyclic All-Carbon Olefins via a Syn-Elimination Approach
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An efficient synthesis of stereodefined tetrasubstituted acyclic all-carbon olefins has been developed via a bis(2,6-xylyl)phosphate formation of stereoenriched tertiary alcohols, followed by in situ syn-elimination of the corresponding phosphates under mild conditions. This chemistry tolerates a wide variety of electronically and sterically diverse substrates and generates the desired tetrasubstituted olefins in high yields and stereoselectivities (>95:5) in most cases. This stereocontrolled olefin synthesis has been applied to the synthesis of anticancer drug tamoxifen in three steps from commercially available 1,2-diphenylbutan-1-one in 97:3 stereoselectivity and 78% overall yield.
- Lim, Ngiap-Kie,Weiss, Patrick,Li, Beryl X.,McCulley, Christina H.,Hare, Stephanie R.,Bensema, Bronwyn L.,Palazzo, Teresa A.,Tantillo, Dean J.,Zhang, Haiming,Gosselin, Francis
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supporting information
p. 6212 - 6215
(2017/11/24)
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- Efficient synthesis of polysubstituted olefins using stable palladium nanocatalyst: Applications in synthesis of tamoxifen and isocombretastatin A4
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A phosphine-free stable palladium nanocatalyst was used for an efficient synthesis of polysubstituted olefins from N-tosylhydrazones and aryl iodides. This methodology was successfully utilized in the synthesis of biologically important tamoxifen and isocombretastatin A4. The nanocatalyst was easily recovered and reused without any apparent loss in size and catalytic activity.
- Ganapathy, Dhandapani,Sekar, Govindasamy
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supporting information
p. 3856 - 3859
(2014/08/18)
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- Structure-function relationships of estrogenic triphenylethylenes related to endoxifen and 4-hydroxytamoxifen
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Estrogens can potentially be classified into planar (class I) or nonplanar (class II) categories, which might have biological consequences. 1,1,2-Triphenylethylene (TPE) derivatives were synthesized and evaluated against 17β-estradiol (E2) for their estrogenic activity in MCF-7 human breast cancer cells. All TPEs were estrogenic and, unlike 4-hydroxytamoxifen (4OHTAM) and Endoxifen, induced cell growth to a level comparable to that of E2. All the TPEs increased ERE activity in MCF-7:WS8 cells with the order of potency as followed: E2 > 1,1-bis(4,4′-hydroxyphenyl)-2-phenylbut-1-ene (15) > 1,1,2-tris(4-hydroxyphenyl)but-1-ene (3) > Z 4-(1-(4-hydroxyphenyl)-1- phenylbut-1-en-2-yl)phenol (7) > E 4-(1-(4-hydroxyphenyl)-1-phenylbut-1-en-2- yl)phenol (6) > Z(4-(1-(4-ethoxyphenyl)-1-(4-hydroxyphenyl)but-1-en-2-yl) phenol (12) > 4-OHTAM. Transient transfection of the ER-negative breast cancer cell line T47D:C4:2 with wild-type ER or D351G ER mutant revealed that all of the TPEs increased ERE activity in the cells expressing the wild-type ER but not the mutant, thus confirming the importance of Asp351 for ER activation by the TPEs. The findings confirm E2 as a class I estrogen and the TPEs as class II estrogens. Using available conformations of the ER liganded with 4OHTAM or diethylstilbestrol, the TPEs optimally occupy the 4OHTAM ER conformation that expresses Asp351.
- Maximov, Philipp Y.,Myers, Cynthia B.,Curpan, Ramona F.,Lewis-Wambi, Joan S.,Jordan, V. Craig
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experimental part
p. 3273 - 3283
(2010/09/09)
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- In(III)-mediated chemoselective dehydrogenative interaction of ClMe 2SiH with carboxylic acids: Direct chemo- And regioselective friedel-crafts acylation of aromatic ethers
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Chemoselective dehydrogenative interaction of ClMe2SiH with a carboxylic acid group in the presence of InX3 is reported. 13C NMR investigation revealed the formation of PhCOOSi(Cl)Me 2as the major transient intermediate. Chemo- and regioselective Friedel-Crafts acylation of aromatic ethers directly from carboxylic acids was established.
- Babu, Srinivasarao Arulananda,Yasuda, Makoto,Baba, Akio
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p. 405 - 408
(2008/02/12)
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- NOVEL COMPOUNDS
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The present invention relates to novel compounds with a variety of therapeutic uses, more particularly novel prodrugs that are particularly useful for delivering a parent compound for selective estrogen receptor modulation.
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Page/Page column 30; 38-40
(2010/02/11)
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- Acylation of aromatic ethers over solid acid catalysts: Scope of the reaction with more complex acylating agents
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Acylation of anisole with 2-phenylbutanoic acid derivatives, over zeolite catalysts, gives the corresponding 4-acyl derivatives with high regioselectivity. In an analogous way, 2,3-dihydrobenzofuran reacts with acid anhydrides or chlorides in the presence
- Smith, Keith,El-Hiti, Gamal A.,Jayne, Anthony J.,Butters, Michael
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p. 2321 - 2325
(2007/10/03)
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- Investigations on estrogen receptor binding. The estrogenic, antiestrogenic, and cytotoxic properties of C2-alkyl-substituted 1,1-bis(4-hydroxyphenyl)-2-phenylethenes
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C2-Alkyl-substituted 1,1-bis(4-hydroxyphenyl)-2-phenylethenes were synthesized and assayed for estrogen receptor binding in a competition experiment with radiolabeled estradiol ([3H]-E2) using calf uterine cytosol. The relative binding affinity decreased with the length of the side chain R = H (3a: 35.2%) > Me (3b: 32.1%) 2CF3 (3d: 5.95%) > n-Pr (3e: 2.09%) > Bu (3f: 0.62%). Agonistic and antagonistic effects were evaluated in the luciferase assay with MCF-7-2a cells stably transfected with the plasmid EREwtcluc. All compounds showed high antiestrogenic activity without significant agonistic potency. The comparison of the IC50 values for the inhibition of E2 (1 nM) documented the dependence of the antagonistic effects on the kind of the side chain: 3a (IC50 = 150 nM), 3b (IC50 = 30 nM), and 3f (IC50 = 500 nM) were weak antagonists, while 3c (IC50 = 15 nM), 3d (IC50 = 9 nM), and 3e (IC50 = 50 nM) were full antiestrogens and antagonized the effect of E2 completely. The most active compound 3d possessed the same antagonistic potency as 4-hydroxytamoxifen (40HT: IC50= 7 nM) without bearing a basic side chain. 3d as well as all other 1,1-bis(4-hydroxyphenyl)-2-phenylalkenes were not able to influence the proliferation of hormone dependent MCF-7 cells despite the antagonistic mode of action. In this assay tamoxifen (TAM) and 40HT reduced the cell growth concentration dependent up to T/Ccorr = 15% and 25%, respectively.
- Lubczyk, Veronika,Bachmann, Helmut,Gust, Ronald
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p. 5358 - 5364
(2007/10/03)
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- Toward a clean alternative to Friedel-Crafts acylation: In situ formation, observation, and reaction of an acyl bis(trifluoroacetyl)phosphate and related structures
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Reaction of acyl trifluoroacetates with phosphoric acid in the presence of trifluoroacetic anhydride (TFAA) leads to the ready formation of acyl bis(trifluoroacetyl)phosphates, which are powerful acylating agents. Formation of these species and the subsequent acylation reaction are carried out, without added solvent, in a single in situ reaction process. In this reaction system, anisole is rapidly acylated at ambient temperature using a variety of carboxylic acids giving the para isomer exclusively. TFAA acts as an activating agent and can be recovered from the reaction system as trifluoroacetic acid (TFA) and converted back to TFAA using a dehydrating agent, while phosphoric acid behaves as a covalent catalyst in the process. This reaction system has many features which are required elements of a clean alternative to the Friedel-Crafts process.
- Smyth, Timothy P.,Corby, Brian W.
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p. 8946 - 8951
(2007/10/03)
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- ortho-Directed electrophilic boronation of a benzyl ketone: the preparation, X-ray crystal structure, and some reactions of 4-ethyl-1-hydroxy-3-(4-hydroxyphenyl)-2-oxa-1-boranaphthalene
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4-Ethyl-1-hydroxy-3-(4-hydroxyphenyl)-2-oxa-1-boranaphthalene (4) is formed in 78percent yield from the reaction of 1-(4-metho-xyphenyl)-2-phenylbutan-1-one with an of excess boron tribromide in dichloromethane followed by treatment with water.Reaction of 4 with iodine in aqueous sodium hydroxide gives a second oxaboracycle, 3-ethyl-1-hydroxy-3-(4-hydroxybenzoyl)-2,1-benzoxaborolane (5).The X-ray crystal structure determinations of both boron heterocycles are reported.Other new compounds reported are 1-(4-hydroxyphenyl)-2-(1-hydroxyphenyl)-butan-1-one (6), formed by reaction of 4 with alkaline hydrogen peroxide, and 1-(4-hydroxyphenyl)-2-(2-biphenyl)-butan-1-one (8), formed by coupling of 4 with bromobenzene in the presence of Pd(PPh3)4.
- Arcus, Vickery L.,Main, Lindsay,Nicholson, Brian K.
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p. 139 - 148
(2007/10/02)
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- The use of Octafluorotoluene and Pentafluoropyridine in the Synthesis of Pure Z and E Isomers of Derivatives of Tamoxifen -1-butene>
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Octafluorotoluene and pentafluoropyridine have been used in the synthesis of pure Z and E isomers of derivatives of the anticancer drug, tamoxifen (1).The isomeric ethers derived by reaction of these perfluoroarenes with an E/Z mixture of 1,2-diphenyl-1-(4-hydroxyphenyl)-1-butene (3) and (4) were easily separated.A process is described for conversion of the E/Z mixtures into one isomer.Cleavage of the ethers regenerated the phenol (3) or (4) of pure stereochemical configuration and the Z-isomer (3) was used for the synthesis of tamoxifen (1) and various monomeric and dimeric analogues.Other perfluoroarenes were less useful.A short synthesis involving early introduction of the perfluorotolyl group is also described.
- Jarman, Michael,McCague, Raymond
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p. 1342 - 1388
(2007/10/02)
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- Acetoxy-substituted 1,1,2-triphenylbut-1-enes with antiestrogenic and mammary tumor inhibiting properties
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1,1,2-Triphenylbut-1-enes (E- and Z-10-12), which are substituted with one p- and one m-acetoxy group in two different aromatic rings, were synthesized. The E and Z isomers were isolated, and their identity was established by 1H NMR spectroscop
- Schneider,Ball,Schonenberger
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p. 1880 - 1885
(2007/10/02)
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- 1,1,2-Triphenylbut-1-enes: Relationship between Structure, Estradiol Receptor Affinity, and Mammary Tumor Inhibiting Properties
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1,1,2-Triphenylbut-1-enes, which are substituted with acetoxy groups on one, two, or three aromatic rings in the para and/or meta positions, were synthesized.The identity of the occurring E and Z isomers were established by 1H NMR spectroscopy.A study on structure-activity relationships was carried out with regard to estradiol receptor affinity and to inhibiting effects on the growth of a postmenopausal human mammary carcinoma implanted in nude mice.The para-substituted compounds generally exhibited a higher receptor affinity and a better antitumor activity than the corresponding meta-substituted ones.The E isomers were superior to the respective Z isomers in those two properties.The tumor-inhibiting effect of the mono-and disubstituted compounds was better than that of the trisubstituted ones.Except for the trisubstituted compounds, they all showed a good correlation between estradiol receptor affinity and antitumor activity.One of the compounds was also tested on the 9,10-dimethylbenzanthracene-induced, hormone-dependent mammary carcinoma of the Spraque-Dawley rat, and the results corresponded to those obtained in the xenograft tumor.
- Schneider, Martin R.,Angerer, Erwin von,Schoenenberger, Helmut,Michel, Ralf Th.,Fortmeyer, H. P.
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p. 1070 - 1077
(2007/10/02)
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