Diastereoselective intramolecular cyclization/Povarov reaction cascade for the one-pot synthesis of polycyclic quinolines.

The method for the synthesis of complex alkaloid-like aza-heterocycles has been developed through the Povarov reaction of in situ generated 2-oxoimidazolium cations. The reaction lead to the formation of 2 C-N, 2 C-C bonds and three stereocentres, and features excellent regio- and diastereoselectivity. Based on the controlled experiments and quantum chemistry data, the mechanism of the reaction cyclization was proposed and diastereoselectivity origins were rationalized. Additionally, a straightforward synthesis of hardly accessible 4,4'-bi(imidazol-2-one) derivatives has been achieved using the same methodology.

Reactions of Aminoacetals with C-Nucleophiles as a New Method for the Synthesis of Di(het)arylmethane Derivatives with a Taurine Fragment.

Based on the acid-catalyzed reaction of functionalized aminoacetals with C-nucleophiles, a series of new diarylmethane derivatives with a taurine fragment were synthesized, the structure of which was established by NMR spectroscopy method.

Oxidative degradation of inorganic sulphides in the presence of a catalyst based on 3,3', 5,5'-tetra-tert-butyl-4,4'-stilbenequinone.

The aim of this study is to monitor the kinetics and mechanism of liquid-phase oxidation of inorganic sulphide by oxygen in the presence of a catalyst based on 3,3',5,5'-tetra-tert-butyl-4,4'-stilbenequinone. The research results point out that this reaction has a first order with respect to each reactant. The effects of temperature, initial sulphide concentration, intermediate and final oxidation products, the nature of inorganic sulphides as well as the catalyst concentration on aqueous sulphide oxidation efficiency were investigated. The catalytic cycle mechanism of sodium sulphide oxidation by 3,3',5,5'-tetra-tert-butyl-4,4'-stilbenequinone is presented.