9 documents found, page 1 of 1
A polymorph of dipeptide halide glycyl-L-alanine hydroiodide monohydrate: cryst...
Baptista, Rosa Maria Ferreira; Gomes, Clara S. B.; Silva, Bruna Machado; Oliveira, joão; Almeida, B. G.; Castro, Maria Cidália RodriguesA polymorph of glycyl-L-alanine HI.H2O is synthesized from chiral cyclo-glycyl-L-alanine dipeptide. The dipeptide is known to show molecular flexibility in different environments, which leads to polymorphism. The crystal structure of the glycyl-L-alanine HI.H2O polymorph is determined at room temperature and indicates that the space group is polar (P21), with two molecules per unit cell and unit cell parameters...
Insights into the anticancer activity of chiral alkylidene-β-lactams and alkyli...
Alves, Américo J. S.; Alves, Nuno G.; Laranjo, Mafalda; Gomes, Clara S. B.; Gonçalves, Ana Cristina; Ribeiro, Ana Bela Sarmento; Botelho, M. FilomenaChiral alkylidene-β-lactams and alkylidene-γ-lactams were synthesized and screened for their in vitro activity against four human cancer cell lines (melanoma, esophageal, lung and fibrosarcoma carcinoma). Alkylidene-β-lactams were synthesized via Wittig reaction of diverse phosphorus ylides with benzhydryl 6-oxopenicillanate, derived from 6-aminopenicillanic acid. Moreover, novel chiral alkylidene-γ-lactams wer...
Synthesis of 5H-chromeno[3,4-b]pyridines via DABCO-catalyzed [3 + 3] annulation...
Soares, Maria I. L.; Gomes, Clara S. B.; Oliveira, M. Conceição; Marçalo, Joaquim; Pinho e Melo, Teresa M. V. D.The DABCO-catalyzed [3 + 3] annulation between 3-nitro-2H-chromenes and benzyl 2,3-butadienoate has been developed as a route to 5H-chromeno[3,4-b]pyridine derivatives. Under optimal reaction conditions, 5H-chromeno[3,4-b]pyridines incorporating two allenoate units were obtained in moderate to good yields (30-76%). The same type of transformation could be carried out using butynoates as allene surrogates. Mecha...
Luminescent halogen-substituted 2-(N-arylimino)pyrrolyl boron complexes: the in...
Rodrigues, Ana I.; Krishnamoorthy, Paramasivam; Gomes, Clara S. B.; Carmona, Nicolas; Di Paolo, Roberto E.; Pander, Piotr; Pina, JoãoA group of new boron complexes [BPh2{κ2N,N′-NC4H3-2-C(H)[double bond, length as m-dash]N-C6H4X}] (X = 4-Cl 4c, 4-Br 4d, 4-I 4e, 3-Br 4f, 2-Br 4g, 2-I 4h) containing different halogens as substituents in the N-aryl ring have been synthesized and characterized in terms of their molecular properties. Their photophysical characteristics have been thoroughly studied in order to understand whether these complexes exh...
Naphthoylhydrazones: coordination to metal ions and biological screening
Ribeiro, Nadia; Galvao, Adelino M.; Gomes, Clara S. B.; Ramos, Helena; Pinheiro, Rute; Saraiva, Lucilia; Ntungwe, Epole; Isca, Vera; Rijo, PatriciaWe report the synthesis of 3-hydroxyl-2-naphthoylhydrazones containing pyrrole (HL1), furane (HL2) and thiophene (HL3) moieties and their V(IV)O-, Cu(II)- and Zn(II)-complexes. All compounds are characterized by the usual analytical techniques and coordination of the ligands to the metal ions is discussed based on spectroscopic data (FTIR, UV-vis, EPR and NMR) as well as CAMB3LYP DFT/TDDFT calculations, indicat...
Reactivity of sarcosine and 1,3-thiazolidine-4-carboxylic acid towards salicyla...
Laia, Fernanda M. Ribeiro; Gomes, Clara S. B.; Melo, Teresa M. V. D. Pinho eThe reaction of sarcosine and 1,3-thiazolidine-4-carboxylic acid with salicylaldehyde-derived alkynes and allenes opened the way to new chromeno[4,3-b]pyrrole and chromeno[2,3-b]pyrrole derivatives. Tetrahydro-chromeno[4,3-b]pyrroles were obtained from the reaction of these secondary amino acids with O-propargylsalicylaldehyde. Interestingly, sarcosine reacted with ethyl 4-(2-formylphenoxy)but-2-ynoate to give ...
Nitrogen-Bridged Heterocycles via Cycloaddition of Non-Classical Heterocyclicfu...
Soares, Maria I. L.; Gomes, Clara S. B.; Melo, Teresa M. V. D. Pinho eThe [4π+2π] cycloaddition of non-classical heterocyclic-fused-[c]thiazoles was explored allowing the synthesis of a range of new nitrogen-bridged bi-, tri- and tetracyclic heterocyclic compounds namely, pyrazolo[1,5-a]pyridines, thiazolo[2,3,4-cd]pyrrolizines and indolizines. For the first time, one non-classical pyrrolo[1,2-c]thiazole was isolated and its structure determined by X-ray crystallography.
2H-Azirines as dipolarophiles
Melo, Teresa M. V. D. Pinho e; Cardoso, Ana L.; Gomes, Clara S. B.; Gonsalves, António M. d'A. Rocha2H-Azirine-3-carboxylates unsubstituted at C-2 act as dipolarophiles in the reaction with diazomethane giving new 4,5-dihydro-3H-pyrazole derivatives. The synthesis of a pyrimidine was also achieved via 1,3-dipolar cycloaddition of methyl 2-bromo-3-phenyl-2H-azirine-2-carboxylate with an azomethine ylide.; http://www.sciencedirect.com/science/article/B6THS-493P1M1-17/1/5df1370edad7138f3cae89fadd9b5c4d
Cycloaddition reactions of 3-aryl-5-phenyl-5H,7H-thiazolo[3,4-c]oxazol-4-ium-1-...
Melo, Teresa M. V. D. Pinho e; Gomes, Clara S. B.; Gonsalves, António M. d'A. Rocha; Paixão, José A.; Beja, Ana M.; Silva, Manuela RamosIntermolecular 1,3-dipolar cycloaddition of (5R)- and (5S)-3,5-diphenyl-5H,7H-thiazolo[3,4-c]oxazol-4-ium-1-olates, (5R)- and (5S)-3-(p-methoxyphenyl)-5-phenyl-5H,7H-thiazolo-[3,4-c]oxazol-4-ium-1-olates with a range of dipolarophiles is described. New chiral 5-aryl-3-phenyl-1H,3H-pyrrolo[1,2-c]thiazoles with R and S configuration were obtained. The structure of methyl (3R)-3-phenyl-5-(p-methoxyphenyl)-1H,3H-py...