23222-97-1Relevant academic research and scientific papers
18F-Labeled Benzyldiamine Derivatives as Novel Flexible Probes for Positron Emission Tomography of Cerebral β-Amyloid Plaques
Li, Zijing,Zhang, Xuran,Zhang, Xiaoyang,Cui, Mengchao,Lu, Jie,Pan, Xiaodong,Zhang, Xianzhong
, p. 10577 - 10585 (2016/12/16)
Early noninvasive visualization of cerebral β-amyloid (Aβ) plaques with positron emission tomography (PET) is the most feasible way to diagnose Alzheimer’s disease (AD). In this study, a series of flexible benzyldiamine derivatives (BDA) were proposed for
Fine tuning of molecular and supramolecular properties of simple trianglimines-the role of the functional group
Gajewy,Szymkowiak,Kwit
, p. 53358 - 53369 (2016/06/14)
Chiral, triangular poly-azamacrocycles (trianglimines) readily available from enantiomerically pure trans-1,2-diaminocyclohexane and various aromatic dialdehydes, differ in their nature and substitution pattern. The highly symmetrical macrocycle having two electron-donating groups attached to the aryl moieties is formed under thermodynamic control that fulfilled the so called entropy of symmetry rule. Conversely, from the 2-nitroterephthaldehyde a kinetic product of trivial C1 symmetry is solely obtained, whereas from 2-methoxyterepthaldehyde a mixture of C3- and C1-symmetrical macrocycles are formed. The factors that contribute to the mechanism of the macrocycle formation were determined on the basis of an experimental/theoretical approach. The non-symmetrical structure of the macrocycle resulted from a symmetrical intermediate that appeared during cyclocondensation. The chiroptical properties of the trianglimines were studied by means of experimental ECD and VCD methods supported by quantum-chemical calculations. The nitro-substituted trianglimine appeared to be a simple, low molecular weight supergelator forming in polar media of stable chiral organogels. The structure of the gel is affected by the nature and chirality of the dopant. The hexaimine macrocycles after reduction of the CN imine bonds formed trianglamines-useful chiral ligands in stereoselective synthesis. The Zn-trianglamine complexes were employed as catalysts for asymmetric hydrosilylation of prochiral ketones, providing products of enantiomeric excess up to 98%. This remains the best result obtained for Zn-diamine catalysed asymmetric hydrosilylation of ketones so far.
Photo-sensitive PMMA microgels: Light-triggered swelling and degradation
Klinger, Daniel,Landfester, Katharina
experimental part, p. 1426 - 1440 (2012/04/23)
Two classes (type A and type B) of novel photolabile divinyl functionalized crosslinkers based on o-nitrobenzyl derivatives were synthesized and investigated with regard to their photolytic performance upon UV irradiation. The systematic variation of the molecular structure resulted in different degradation rates depending on the irradiation conditions. Thus, the successive and independent cleavage is enabled by either adjusting the applied wavelengths or irradiation times. The respective molecules were used to build up photodegradable PMMA microgels by free radical copolymerization with MMA in a miniemulsion polymerization process. UV light-induced degradation of the swollen microgels was monitored by time dependent turbidity measurements and the resulting kinetics were found to correlate with the photolysis rates of the respective crosslinkers in solution. The irradiation wavelength-controlled selective partial cleavage of type B crosslinking points was achieved by UV irradiation with λ > 315 nm and resulted in particles with extensively increased volumes consisting of highly swollen networks. In addition, the irradiation time-controlled selective complete degradation of particles containing type B crosslinkers was accomplished. By using broadband UV light containing wavelengths of λ 315 nm, the successive complete particle disintegration of type B and type A microgels was observed. Hence, the specific performance of the synthesized microgels can be precisely triggered by means of the used UV light wavelengths, doses and intensities, thus representing a great potential as new light-responsive nanoscaled materials.
Synthesis of a new hydrophilic o-nitrobenzyl photocleavable linker suitable for use in chemical proteomics
Piggott, Andrew M.,Karuso, Peter
, p. 8241 - 8244 (2007/10/03)
Linkers currently used in solid phase synthesis are generally short and hydrophobic, limiting their usefulness in biological systems. Herein, we describe a facile synthesis of a long, hydrophilic, o-nitrobenzyl photocleavable linker, suitable for construc
