Séminaire par le Pr Yuriy Shermolovich / Laboratoire des composés organosoufrés - Institut de chimie organique / Kiev - Ukraine
Lundi 28 mai 2018 - 14h - salle Maroni / MHT
Pr Yuriy Shermolovich, chercheur au Laboratoire des composés organosoufrés à Kiev, est accueilli pendant 1 mois aux IMRCP. Il fera une présentation sur : Sulfur containing reagents for fluorinated heterocycles synthesis
The presentation concerns first the synthetic possibilities of simple 1,1-dihydropolyfluoroalkyl sulfides RfCH2SR, sulfones RfCH2SO2R and fluorinated thiocarboxylic acid derivatives. Dithioesters and thioamides, RfCSSR and RfCSNR2, are used to prepare different fluorinated heterocyclic compounds such as: 1,2,3-triazoles, pyrazoles, imidazoles, thiazoles, uracils, pyrimidines, thiopyranes, dihydrithiopyranes, oxathiines, tetrathiafulvalenes.
A series of chiral S- or O-alkyl thionoesters have been synthesized by treatment of trifluorothioacetyl- or 2,2,3,3-tetrafluorothiopropionyl chloride with corresponding thiols or alcohols. The thia-Diels-Alder reaction of the thionoesters with symmetrical 1,3-dienes proceeds with diastereoselectivity up to 60%. Structures of cycloaddition products and corresponding transition states have been studied at the DFT level of approximation. The experimentally observed diastereomeric excess has been referred to differences in activation energies of transition states, preceding formation of the diastereomeric cycloaducts.
