- Stereoselective synthesis of triarylethylenes via copper-palladium catalyzed decarboxylative cross-coupling: Synthesis of (Z)-tamoxifen
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The first Cu/Pd-catalyzed decarboxylative cross-coupling of 3,3-diarylacrylic acids with aryl bromides is described. Triarylethylenes were obtained in high yields with excellent stereoselectivities. This methodology was successfully applied to the stereos
- Cahiez, Gérard,Moyeux, Alban,Poizat, Ma?l
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supporting information
p. 8982 - 8984
(2014/08/05)
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- Trans-stilbene as a starting material for the synthesis of tamoxifen based on palladium-catalyzed cross-coupling reactions
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(Z)-Tamoxifen was synthesized from a simple olefin (trans-stilbene) in 5 steps and 40% overall yield (Z/E = 74:26). The phenyl substituted group (4-Me2NCH2CH2OC6H4) was attached by a bromination-dehydrobromination-Suzuki reaction sequence. Subsequently, the ethyl group was attached to the triarylated olefin by a bromination-Negishi reaction sequence. Both the Suzuki and Negishi cross-coupling processes are stereospecific, and the stereo-selectivity depends only on the bromination-dehydrobromination reactions. (Z)-Tamoxifen was also obtained from trans-stilbene in only 3 steps by using Heck reaction-bromination- Negishi reaction sequence in 57% overall yield (Z/E = 65:35). Georg Thieme Verlag Stuttgart.
- Nunes, Carolina M.,Limberger, Jones,Poersch, Silvia,Seferin, Marcus,Monteiro, Adriano L.
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experimental part
p. 2761 - 2765
(2010/01/21)
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- Hydroxy derivatives of tamoxifen
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In the exploration of the structural features that affect the RBA (binding affinity for the estrogen receptor of rat uterus relative to that of estradiol) in the tamoxifen [trans-(Z)-1-[4-(dimethylamino)ethoxy]-1,2-diphenyl-1-butene] series, several derivatives variously substituted in the 1-phenyl group have been synthesized. In the tamoxifen series, the descriptors E and Z, which define the configuration of the geometrical isomers and depend on the location and nature of substituents in the aromatic moieties and the ethyl group, may vary, although the relative configuration (cis or trans) does not. In order to avoid confusion the terms cis and trans will be used in this paper to refer to the relative positions of the 4-[2-(dimethylamino)ethoxy]phenyl and ethyl (or hydroxyethyl, hydroxypropyl, or bromo) substituents attached to the ethene moiety]. The final stage of each synthesis involved acid-catalyzed dehydration of a tertiary alcohol, and, in contrast to the known 3- and 4-hydroxy derivatives which were obtained as near-equimolar cis,trans mixtures, only the trans forms of the 2-hydroxy, 2-methyl, 2,4-dihydroxy, and 4-hydroxy-2-methyl derivatives were obtained. Also, in contrast to the trans forms of the 3- and 4-hydroxy derivatives, which are readily equilibrated to cis,trans mixtures, the trans 2-hydroxy derivative could not be isomerized. Tamoxifen and 2-methyltamoxifen had similar RBA's (~1% of that of E2), but that of 2-hydroxytamoxifen was much lower (0.1%). Introduction of a second hydroxyl group (2,4-dihydroxy derivative) enhanced the RBA, and for the 4-hydroxy-2-methyl derivative, the RBA and growth inhibitory activity against the MCF-7 mammary tumor cell line in vitro were high and comparable to those of 4-hydroxytamoxifen, a metabolite of the parent drug. Tamoxifen derivatives hydroxylated at positions 3 or 4 of the 1-butene moiety and the 5-hydroxy-1-pentene analogue were also synthesized, but they had very low RBA values.
- Foster,Jarman,Leung,McCague,Leclercq,Devleeschouwer
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p. 1491 - 1497
(2007/10/02)
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