Teses em Química (Doutorado) - PPGQ/UNICAMP
URI Permanente para esta coleçãohttps://repositorio.ufpa.br/handle/2011/9747
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Item Acesso aberto (Open Access) Síntese e atividade biológica de neolignanas 8.0.4' derivados e compostos correlatos(Universidade Estadual de Campinas, 1991-07-03) SANTOS, Lourivaldo da Silva; BARATA, Lauro Euclides Soares; http://lattes.cnpq.br/1609747051706094We have synthesized ca. 80 different aromatic compounds (8.0.4' -neolignans several derivatives and correlated compounds containing or 5 at C-8). These substances were submitted to bioassays namely PAF antagonists anti-leishmaniasis antibacteria, anti-schistossomose and anti-fungi. From the Virola surinmensin leaves we have isolated a 8.0.4' -neolignan, (+) -surinamensin whose absolute configuration was determinated as (+)-7S, 8S-surinamensin. Using crown ethers associated with metalic hydrides we have performed studies on the reduction stereoselectivity aiming a high diastereoselectivity of the β-ketoether reductions. We have also developed the first synthetic pathway Ieading to the enantiomerically pure 8.0.4' -neolignans using (+) - and (-) -Dimethyl tartrate as the chiral auxiliary groups which was sucessfulIy applied to the synthesis of (+) -virolin. Also we obtained chiral β -ketosulfides using the same route described earlier in an enantiosselectice pathway. Finnally, using safrol and eugenol abundant Brazilian raw material, we developed an alternative synthetic rout to the neolignans having bromohydrin as intermediate.Item Acesso aberto (Open Access) Síntese, caracterização e termoquímica de adutos entre metil, N, N'-dimetil e tetrametiluréia com haletos de zinco, cádmio e mercúrio-II(Universidade Estadual de Campinas, 1980) ASSUNÇÃO, Francisco Pereira; AIROLDI, Claúdio; http://lattes.cnpq.br/1481366755849386The reactions of zinc, cadmium and mercury halides with the ligands methylurea (MU), N, N'-dimethylurea (DMU) and tetramethylureia (TMU) yielded the following adducts: 2nL2x2, MLX2 (M + Cd, Hg) (X =Cl, Br and L=MU, DMU and TMU), M(TMU) 2I2 (M + Zn, Cd),Cd (DMU) 3Br3 and Hg (DMU) 2Cl2. These adducts were characterized by elemental analyses, melting points, conductance measurements, thermogravimetric. ifra red spectra and mass spectra. From the values os standard enthalpies of dissolution of thehalides,ligands and adducts in suitable calorimetric solvents, the standard enthapy of the reactions was calculated: MX2(s) + nL (l,s) = MLnX2 (s); ΔHθR. For the obtention of the standard enthalpies of formation ΔHθf of the adducts ΔHθR values were used. It was also necessary to determine the standard enthalpies of formation of DMU and MU, which were obtained by means of combustion calorimetry. The standard enthalpies, ΔHθD and ΔHθM, for the equations below were also calculated, howerer, it was necessary to determine the standard enthapy of vaporation of TMU and the standard enthalpies of sublimation of DMU and MU. MLnX2(s) + Mx2(s) + nL(g) ; ΔHθD. MLnX2(s) + Mx2(s) + nL(g) ; -ΔHθM. The thermal data in conjution with the mass spectra of the adducts suggest that possibility these compouds do not exist, at least in appreciable amounts in the gaseous phase. However, the enthalpy of the metal-oxigen bond was estimated, based on the fact that this mode of coordenation has occured with these three ligands, in agreement with the infra red results. The ΔHθR parameter establiches the order of basicity, TMU>DMU>MU, and the acidity order of of the metals, Zn>Cd>Hg.