A new series of indole-based pyranoquinoline derivatives P1-24 has been synthesized by a one-pot cyclocondensation reaction of 2-(4-substituted)phenyl-N-allyl-indole-3-carbaldehydes 1a-d; active methylenes 2a-c; and 4-hydroxy-1-substituted quinolin-2(1H)-one 3a-b catalysed by an organocatalyst tetra-n-butylammonium fluoride (TBAF) in aqueous ethanol. The easy experimental procedure of the react...

β,β-Disubstituted-1,3-dinitro compounds were obtained exclusively with an overall yield of 83% through a domino nitroaldol/elimination/1,4-addition process, when excess nitromethane was added to cyclohexanone or butanone using DBU (1,8-diazabicyclo[5.4.0]undec-7-ene), as basic catalyst. On the other hand, β-nitroalcohols could be in 30-84% yield, reacts different aliphatic ketones stoichiometri...

Background and aim: Orthodontic treatment these days is increasing in demand, and therefore, it is relatively imperative for the orthodontist to prescribe the use of fluoride-containing products, such as mouthwashes and gels, to help prevent dental caries and maintain healthy oral health. The aim of the study was to assess and evaluate the effects of fluoride prophylactic agents on mechanical p...

This paper presents the results of research on development a technology intended to process electric smelting dusts ilmenite concentrate with extraction silicon and titanium production products in form their dioxides. Dusts were processed for separation using ammonium fluoride method. The optimum conditions fluorination sublimation compounds from dust determined: temperature 260 °С, 6 h duratio...

ABSTRACT Acetonolysis of the titanium tetrachioride complex of lycopene gives s-carotene and e.carotene. Analogous cyclization reactions have been achieved with y-carotene, rubixanthin esters and f3-zeacarotene. In some typical parasitic plants and semi-parasitic plants, carotenoids with a-structures predominate over those with fl-structures. The formation of carotenoid epoxides is favoured in ...

The high field strength elements (HFSE, i.e. Ti, Zr, Hf, Nb, Ta, W, Th) reside in minerals that are traditionally considered to be nominally insoluble in aqueous fluids, but in recent years experimental and field-based evidence to the contrary has been presented. Here, first principles molecular dynamics simulations are used to demonstrate that at low concentrations both fluoride and chloride f...

The effects of fluoride concentrations and pH on the corrosion behavior of pure titanium, Ti-6Al-4V, Ti-6Al-7Nb alloys and a new Ti alloy adding palladium, which is expected to promote a repassivation of Ti were examined by anodic polarization and corrosion potential measurements. The amount of dissolved Ti was analyzed by inductively coupled plasma mass spectroscopy. The surface of the specime...