Density functional theory investigations on acid-catalysed epoxide oxidative ring-opening by DMSO. Competition between oxidation processes

Novel DFO-SAM on mesoporous silica for iron sensing. Part I. Synthesis optimization and characterization of the material

The synthesis and the physico-chemical characterisation of a novel solid phase, designed for iron(iii) sorption, are presented. The solid (indicated in the following as DFO-SAMMS) is made with a hydroxamate siderophore, the deferoxamine (DFO), covalently bound on a self-assembled monolayer on mesoporous silica (SAMMS). The data demonstrate that the DFO molecules are bound to the solid material, grafted on the surface and do not enter the silica pores. A new one-pot synthesis is presented in which DFO is dissolved in DMSO, and left to react with GPTMS with stirring overnight. In the same mixture, SAMMS is added to get the final product. The optimisation of experimental conditions of this novel one-pot synthesis is presented, with results indicating that a temperature of 90 °C, for the reaction between DFO and GPTMS, and the use of MCM-41 silica are the most convenient conditions. The kinetics of sorption reveals that the iron uptake is relatively fast, around 100 min at pH = 2.5, and from the sorption profile of iron(iii), the estimated capacity of the product obtained under optimized conditions was higher than 0.3 mmol g(-1). The results found in the present research are very promising for application in real biological samples.

Benzo[cd]azulene skeleton: azulene, heptafulvene, and tropone derivatives

Due to our interest in protein kinase modulating compounds, we developed syntheses for benzo[cd]azulenes. By using very common catalysts and reagents, such as t-BuOK, HCl, and mCPBA, the commercially available guaiazulene is converted in three steps into tricyclic tropone derivatives. Electrophilic aromatic substitution reactions of guaiazulene proceed without a catalyst. Complex one-pot reactions convert 1'-hydroxyalkyl azulenes into tricyclic heptafulvenes, and finally, the mild oxidant mCPBA cleaves the semicyclic C horizontal lineC double bonds to furnish tropones.