RESUMEN
[2]Rotaxanes with large macrocyclic phenanthrolines were prepared by the template method, and the stability of the rotaxanes was examined. Compared to the tris(biphenyl)methyl group, the tris(4-cyclohexylbiphenyl)methyl group was a larger blocking group, and the rate of the dissociation of the components decreased significantly when the thermal stability of a rotaxane with a 41-memebered ring was examined. We also succeeded in the synthesis of larger rotaxanes by the oxidative dimerization of alkynes with these bulky blocking groups, utilizing the catalytic activity of the macrocyclic phenanthroline-Cu complex.
Asunto(s)
Cobre/química , Compuestos Macrocíclicos/química , Compuestos Macrocíclicos/síntesis química , Compuestos Organometálicos/química , Compuestos Organometálicos/síntesis química , Fenantrolinas/química , Rotaxanos/química , Rotaxanos/síntesis química , Catálisis , Dimerización , Espectroscopía de Resonancia Magnética , Modelos Moleculares , Estructura MolecularRESUMEN
Two new synthetic pathways to the anti-cancer agent tamoxifen and its derivatives were developed. The first route involved the aldol reaction of benzyl phenyl ketone with acetaldehyde followed by Friedel-Crafts substitution with anisole in the presence of Cl(2)Si(OTf)(2) to produce 1,1,2-triaryl-3-acetoxybutane, a precursor of the tamoxifen derivatives. The second one utilized the novel three-component coupling reaction among aromatic aldehydes, cinnamyltrimethylsilane, and aromatic nucleophiles using HfCl(4) as a Lewis acid catalyst to produce 3,4,4-triarylbutene, that is also a valuable intermediate of the tamoxifen derivatives. The former strategy requires a total of 10 steps from the aldol formation to the final conversion to tamoxifen, whereas the latter needs only three or four steps to produce tamoxifen and droloxifene including the installation of the side-chain moiety and the base-induced double-bond migration to form the tetra-substituted olefin structure. This synthetic strategy seems to serve as a new and practical pathway to prepare not only the tamoxifen derivatives but also the other SERMs (selective estrogen receptor modulators) including estrogen-dependent breast cancer and osteoporosis agents.