Journal of the Serbian Chemical Society 2004 Volume 69, Issue 11, Pages: 909-918
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Thionation of N-methyl- and N-unsubstituted thiazolidine enaminones
Marković Rade, Rašović Aleksandar S., Baranac Marija M., Stojanović Milovan, Steel Peter, Jovetić Stanka L.
The potential of directional non-bonded 1,5-type S···O interactions to initiate the incipient stage of an in situ rearrangement of N-unsubstituted thiazolidine enaminones to functionalized 1,2-dithioles has been demonstrated. The spectral characteristics, as well as X-ray structural analysis of a selected rearranged product, indicate that a dynamic interconversion occurs in solution between the 1,2-dithiole and the 3,3aλ4,4-trithia-1-azapentalene bicylic form. The lack of the rearrangement in the case of a N-methyl substituted enaminone precursor is attributed to an unfavorable methyl migration in the last reaction step.
Keywords: thiazolidine, enaminone, Lawesson’s reagent, 1,2-dithiole, 3, 3aλ4,4-trithia