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171.
Shujuan Jin Olivier St-Jean Sandra I. Baltatu Vijayaratnam Santhakumar Mirosław J. Tomaszewski 《Tetrahedron letters》2012,53(10):1278-1281
Several 3-substituted pyrido[1,2,5]triazepin-4-ones and their benzo counterparts have been prepared in three steps from commercial starting materials. The key step involves SNAr-type intramolecular nucleophilic aromatic substitution of the appropriate hydrazone substrates. 相似文献
172.
Delphine Catel Olivier Payen Floris Chevallier Florence Mongin Philippe C. Gros 《Tetrahedron》2012,68(21):4018-4028
Butyl and dibutylmagnesiates incorporating chiral ligands have been prepared and their reactivity studied. The reagents were efficient to promote the clean bromine–magnesium exchange of azinyl bromides at room temperature and subsequent reaction with aldehydes affording pyridylcarbinols. (R,R)-TADDOL-based dibutylmagnesiate was the best reagent leading to acceptable to good enantioselectivities, depending on the substrate and on the aldehyde substitution. This is the first example of enantioselective addition of in situ generated pyridylmagnesiate to carbonyl electrophiles. 相似文献
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175.
Jorge Mejia Frans Tichelaar Christelle Saout Olivier Toussaint Bernard Masereel Zineb Mekhalif Stéphane Lucas Joseph Delhalle 《Journal of nanoparticle research》2011,13(2):655-667
Multi-walled carbon nanotubes (MWCNTs) were dispersed in water and in a Pluronic F108 solution by four different dispersion
methods (stirring, bath sonication, stirring followed by bath sonication, and sonication probe). The effect of the dispersion
methods were evaluated in terms of the particle size distribution, the agglomerates size, and the exfoliated fraction produced,
as well as in terms of the surface and bulk chemical composition. Energy dispersive X-ray, X-ray photoelectron spectroscopy,
and centrifugal liquid sedimentation techniques were used to characterize pristine MWCNTs and their dispersion. It is shown
that, irrespective of the dispersion methods used, the MWCNTs are strongly wrapped with the biocompatible surfactant Pluronic
F108, thereby modifying the external surface of the MWCNTs. Some shortening of MWCNTs and more wrapping are also observed
when sonication methods are used. These observations raise questions as to the validity of results obtained in toxicology
tests, in vitro and in vivo, were such methods of dispersion procedures are used. 相似文献
176.
Modulation of the Physicochemical Properties of Donor–Spiro–Acceptor Derivatives through Donor Unit Planarisation: Phenylacridine versus Indoloacridine—New Hosts for Green and Blue Phosphorescent Organic Light‐Emitting Diodes (PhOLEDs)
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Dr. Sébastien Thiery Dr. Denis Tondelier Bernard Geffroy Dr. Olivier Jeannin Dr. Joëlle Rault‐Berthelot Dr. Cyril Poriel 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(29):10136-10149
This work reports a detailed structure–property relationship study of a series of efficient host materials based on the donor–spiro–acceptor (D‐spiro‐A) design for green and sky‐blue phosphorescent organic light‐emitting diodes (PhOLEDs). The electronic and physical effects of the indoloacridine (IA) fragment connected through a spiro bridge to different acceptor units, namely, fluorene, dioxothioxanthene or diazafluorene moiety, have been investigated in depth. The resulting host materials have been easily synthesised through short, efficient, low‐cost, and highly adaptable synthetic routes by using common intermediates. The dyes possess a very high triplet energy (ET) and tuneable HOMO/LUMO levels, depending on the strength of the donor/acceptor combination. The peculiar electrochemical and optical properties of the IA moiety have been investigated though a fine comparison with their phenylacridine counterparts to study the influence of planarisation. Finally, these molecules have been incorporated as hosts in green and sky‐blue PhOLEDs. For the derivative SIA‐TXO2 as a host, external quantum efficiencies as high as 23 and 14 % have been obtained for green and sky‐blue PhOLEDs, respectively. 相似文献
177.
A synthetic tris-(bis-(aminomethyl)pyridine) receptor was prepared in excellent yields via reversible imine condensation strategy. Catalytic activity in Henry reactions of the corresponding copper(II) complex was studied. Capitalizing on previous works by Anslyn with related receptors, the dramatic increase in basicity induced by this type of complex on diketo-derivatives was used to perform a nucleophilic addition of a deprotonated substrate onto an electrophile within the cavity. Hence, a Lewis acid stabilized nitronate was reacted with various aldehydes. A notable preference for small reactants easily accommodated in the cavity over encumbered ones was observed, thus representing an example of substrate-selectivity. 相似文献
178.
Jean-Pierre Jolivet Sophie Cassaignon Corinne Chanéac David Chiche Olivier Durupthy David Portehault 《Comptes Rendus Chimie》2010,13(1-2):40-51
The aim of this paper is to show that a very simple but well controlled chemistry in an aqueous medium allows one to efficiently control the main characteristics of oxide nanoparticles. Examples concerning titania, alumina, iron and manganese oxides are discussed to illustrate various effects on the control of size, shape and structure of nanoparticles. Some examples of functionalization of these particles are also illustrated. Experimental data, procedures and detailed references can be found in the cited literature. 相似文献
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