Analysis of regioisomers of α-O- and α-N-substituted oxazolidines using tandem mass spectrometry with electron impact and ammonia chemical ionization

Fragmentations induced by collision-activated dissociation of α-O- and α-N-substituted oxazolidines are demonstrated under ammonia chemical ionization (CI) and electron impact (El) conditions. Discrimination of these regioisomers is achieved using either conventional EI mass spectra or daughter ion mass spectra of the protonated molecules under ammonia CI conditions.     

Synthèse et tautoméric d'amino-3 et d'hydroxy-3 buténolide

The synthesis fo 3-amino- and 3-hydroxy-2-methyl-4,4-spiro-cyclohexane-2-butene-4-olide was achieved starting from isocyanate or an isocyanate precursor. The study and discussion of tautomeric structures were peformed using ir and nmr spectra functional groups reactivity.     

A new route to 5,6-diarylpyridazin-3-ones by metalation and cross-coupling of pyridazines

Starting from 3,6-dichloropyridazine, a new route is described to antihypertensive 5,6-diarylpyridazin-3-ones. This pathway comprises the regioselective metalation followed by a substitution of the trimethylsilyl moeity. The introduction of iodine by another metalation allowed the cross coupling of arylboronic acids. The 6-methoxy group was then cleaved to afford the pyridazinones.     

A Direct Synthesis of Substituted α - Allenic Carboxanilides from Allenyllithium Reagents

The metalation of various allenic hydrocarbons and the subsequent reaction of the lithioderivatives with phenyl isocyanates as a synthetic route to α - allenyl carboxanilides is described. The best results were obtained with 3,3-disubstituted propadiene and 3,3,1-trisubstituted propadiene.     

Fabrication of zinc oxide nanowires/polymer composites by two‐photon polymerization

We present an approach to fabricate ZnO nanowires/polymer composite into three‐dimensional microstructures, based on two‐photon polymerization direct laser writing, a fabrication method that allows submicrometric spatial resolution. The structural integrity of the structures was inferred by scanning electron microscopy, while the presence and distribution of ZnO nanowires was investigated by energy dispersive X‐ray, Raman spectroscopy, and X‐ray diffraction. The optical properties of the produced composite microstructures were verified by imaging the characteristic ZnO emission using a fluorescence microscope. Hence, such approach can be used to develop composite microstructures containing ZnO nanowires aiming at technological applications. © 2013 Wiley Periodicals, Inc. J. Polym. Sci. Part B: Polym. Phys. 2014 , 52, 333–337