源自氨基酸的简单拟肽分子在乙腈中与间位和对位双(溴甲基)苯反应,非常有效地产生大环结构。环化反应不需要高稀释技术,并且似乎对形成的大环的大小不敏感。通过 (1)H NMR、单晶 X 射线衍射、荧光测量和分子力学获得的数据分析表明,折叠构象可以预先组织系统以实现有效的环化。分析了在折叠构象存在下分子内氢键和疏溶剂效应所起的作用。
Silver complexes of peptidomimetic polyazapyridinophanes. The influence of the bonding cavity size and the nature of side chains
作者:Ignacio Alfonso、Isabel Burguete、Santiago V. Luis、Juan F. Miravet、Piotr Seliger、Ewa Tomal
DOI:10.1039/b512762a
日期:——
Several peptidomimetic macrocycles containing a pyridine spacer and ring sizes ranging from 15 to 17 have been efficiently synthesized starting from valine and phenylalanine. The complexes formed have been investigated by potentiometry and NMR. Log K values show that phenylalanine derivatives 8 are consistently more stable than valine derivatives 7, whilst macrocycles with ring sizes of 16 members are the most appropriate for the complexation. The NMR data, in combination with molecular modeling, allow rationalization of the structure of the complexes formed and the participation of the aromatic rings from the side chain of phenylalanine in π-Ag+ interactions to be discarded.
New chiral tetraaza ligands for the efficient enantioselective addition of dialkylzinc to aromatic aldehydes
作者:M. Isabel Burguete、Jorge Escorihuela、Santiago V. Luis、Agustí Lledós、Gregori Ujaque
DOI:10.1016/j.tet.2008.07.099
日期:2008.10
enantioselective addition of dialkylzinc to aldehydes. These bis(amino amide) ligands show high enantioselectivity in the addition of organozincs to aromatic aldehydes. Different structural elements on the ligands seem to play an important role in determining the observed enantioselectivity. Ligand 4b (N,N′-bis(N-l-valinyl)-1,3-diaminopropane, with an aliphatic spacer with 3C atoms) catalyzed the addition of Et2Zn
Molecular Hydrogels from Bolaform Amino Acid Derivatives: A Structure-Properties Study Based on the Thermodynamics of Gel Solubilization
作者:Vicent J. Nebot、José Armengol、Johan Smets、Susana Fernández Prieto、Beatriu Escuder、Juan F. Miravet
DOI:10.1002/chem.201103193
日期:2012.3.26
Insight is provided into the aggregation thermodynamics associated to hydrogel formation by molecular gelators derived from L‐valine and L‐isoleucine. Solubility data from NMR measurements are used to extract thermodynamic parameters for the aggregation in water. It is concluded that at room temperature and up to 55 °C, these systems form self‐assembled fibrillar networks in water with quite low or
作者:Jorge Becerril、M. Isabel Burguete、Beatriu Escuder、Francisco Galindo、Raquel Gavara、Juan F. Miravet、Santiago V. Luis、Gabriel Peris
DOI:10.1002/chem.200400031
日期:2004.8.20
The self-assembly of a series of smallpeptidomimeticcyclophanes in organic solvents was studied. X-ray diffraction, NMR spectroscopy, and molecular modelling were used to understand the structural features of these self-assembling compounds both at the molecular and supramolecular level. The factors that could influence the formation of gels rather than crystals were studied and a model for the arrangement
Minimalist peptidomimetic cyclophanes as strong organogelators
作者:Jorge Becerril、M. Isabel Burguete、Beatriu Escuder、Santiago V. Luis、Juan F. Miravet、Manel Querol
DOI:10.1039/b111229e
日期:2002.3.21
L-Valine containing cyclophanes have been shown to gelate organic solvents leading to soft materials with a clear expression of their chirality at the supramolecular level.