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Concise construction of novel bridged bicyclic lactams by sequenced Ugi/RCM/Heck reactions 总被引:1,自引:0,他引:1
Ribelin TP Judd AS Akritopoulou-Zanze I Henry RF Cross JL Whittern DN Djuric SW 《Organic letters》2007,9(24):5119-5122
Herein we report a concise protocol for the diastereoselective synthesis of novel bridged bicyclic lactams from commercially available components by the sequence of Ugi, ring-closing metathesis (RCM), and Heck reactions. X-ray diffraction studies revealed that the bicyclic products contain varying degrees of pyramidalization of the bridgehead nitrogen atom. 相似文献
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Irini Michelakaki Stavros Pissadakis 《Applied Physics A: Materials Science & Processing》2009,95(2):453-456
The effect of 193 nm excimer laser radiation on the Knoop hardness and the elastic modulus of an ultra-phosphate glass is
presented here. The experimental results reveal that the glass matrix undergoes a significant softening and volume dilation
process for highly accumulated energy doses, where the Knoop hardness reduces by more than 15%, while following a single photon
absorption rule. Further, during the early stages of the exposure a slight hardening process is observed. Finally, the elastic
modulus is correlated with respect to the measured Knoop hardness. 相似文献
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In order to model the experimental compaction of clays as completely as possible, it is necessary to use the hydromechanical coupled three-dimensional theory for saturated porous media. The proposed formulation is based on elastoplasticity, more precisely on modified Cam-clay model. The identification of the parameters of the model is made by special oedometric experiments at steady state. The compaction experiments are simulated with accuracy in transient and steady states and complement those obtained in a recent study based only on steady state. 相似文献
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McSparron H Blythe MJ Zygouri C Doytchinova IA Flower DR 《Journal of chemical information and computer sciences》2003,43(4):1276-1287
JenPep is a relational database containing a compendium of thermodynamic binding data for the interaction of peptides with a range of important immunological molecules: the major histocompatibility complex, TAP transporter, and T cell receptor. The database also includes annotated lists of B cell and T cell epitopes. Version 2.0 of the database is implemented in a bespoke postgreSQL database system and is fully searchable online via a perl/HTML interface (URL: http://www.jenner.ac.uk/JenPep). 相似文献
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George P. Karayannidis Dimitris S. Achilias Irini D. Sideridou Dimitris N. Bikiaris 《European Polymer Journal》2005,41(2):201-210
In this investigation the production of secondary value-added products, such as alkyd resins, derived from the glycolysis of poly(ethylene terephthalate) (PET) is examined as an effective way for its recycling. PET was taken from common soft-drink bottles and diethylene glycol (DEG) was used for the depolymerization at several initial molar ratios. The oligomers obtained were analyzed according to their average molecular weights. Furthermore, the glycolyzed PET products (oligomers) were reacted with maleic anhydride, phthalic anhydride and propylene glycol to form unsaturated polyester resins. These were subsequently mixed with styrene and cured using the benzoyl peroxide/amine initiator system to carry out the reaction in ambient temperature. The curing characteristics of the resins produced were investigated with respect to the initial molar ratio of DEG/PET as well as the initial initiator concentration. Finally, the mechanical properties (tensile strength and elongation at the break point) of the resins were compared with the conventional general purpose resin and were found to be comparable. 相似文献
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The 3D-QSAR CoMSIA technique was applied to a set of 458 peptides binding to the five most widespread HLA-A2-like alleles: A*0201, A*0202, A*0203, A*0206 and A*6802. Models comprising the main physicochemical properties (steric bulk, electron density, hydrophobicity and hydrogen-bond formation abilities) were obtained with acceptable predictivity (q
2 ranged from 0.385 to 0.683). The use of coefficient contour maps allowed an A2-supermotif to be identified based on common favoured and disfavoured areas. The CoMSIA definition for the best HLA-A2 binder is as follows: hydrophobic aromatic amino acid at position 1; hydrophobic bulky side chains at positions 2, 6 and 9; non-hydrogen-bond-forming amino acids at position 3; small aliphatic hydrogen-bond donors at position 4; aliphatic amino acids at position 5; small aliphatic side chains at position 7; and small aliphatic hydrophilic and hydrogen-bond forming amino acids at position 8. 相似文献
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Irini Akritopoulou-Zanze Alan Whitehead Jan E. Waters Rodger F. Henry Stevan W. Djuric 《Tetrahedron letters》2007,48(20):3549-3552
We report the synthesis of highly functionalized 3,4-dihydroquinolin-2(1H)-ones via sequential Ugi/acrylanilide photocyclization reactions. The [6π]-photocyclization proceeds in excellent yields and with preferential trans-selectivity for the newly formed ring system. 相似文献