Reaction of N-sulfinyltrifluoromethanesulfonamide with carbodiimides: Formation of N-trifluoromethanesulfonyl-2,4-dialkyl-1,2,4-thiadiazetidin-3-imine 1-oxides

• Published in: Journal of fluorine chemistry 2012-08, Vol.140, p.59-61
• Main Authors: Shainyan, Bagrat A., Tolstikova, Ljudmila L.
• Format: Article
• Language: English
• Subjects: 1,2,4-Thiadiazetidin-3-imine 1-oxides; Carbodiimides; Mechanism; N-sulfinyltrifluoromethanesulfonamide; Structure; Synthesis
• ISSN: 0022-1139; 1873-3328
• DOI: 10.1016/j.jfluchem.2012.04.016

N-sulfinyltrifluoromethanesulfonamide reacts with N,N′-dialkylcarbodiimides via the ring opening – ring closure sequence of the intermediate adduct to give N-trifluoromethanesulfonyl-2,4-dialkyl-1,2,4-thiadiazetidin-3-imine 1-oxides. [Display omitted] ► Condensation of N-sulfinyltriflamide with N,N′-dialkylcarbodiimides was studied. ► The products were shown to have the structure of symmetrically substituted N-triflyl-2,4-dialkyl-1,2,4-thiadiazetidin-3-imine 1-oxides. ► The mechanism including [2π+2π] cycloaddition and the ring opening – ring closure of the intermediate cycloadducts was proposed. N-sulfinyltrifluoromethanesulfonamide was found to react with diisopropyl- and dicyclohexylcarbodiimides with the formation of N-trifluoromethanesulfonyl-2,4-dialkyl-1,2,4-thiadiazetidin-3-imine 1-oxides. The mechanism includes the [2π+2π] cycloaddition resulting in 2-trifluoromethanesulfonyl-3-alkylimino-4-alkyl-1,2,4-thiadiazetidine 1-oxides, the ring opening of the latter, rotation about the CN bond and the ring closure to the final products.