Reactions of quadricyclane with fluorinated nitrogen-containing compounds. Synthesis of 3-aza-4-perfluoroalkyl-tricyclo[4.2.1.02,5]non-3,7-dienes

Cycloaddition reaction of quadricyclane and fluoroolefins

“…The same trend is observed in 19 F NMR spectra of compounds 5a, b, 7a, b, 11a, b (see Table 1), for which the resonances of fluorines in the anti-position (minor isomers) are always shifted downfield relative to the resonances of syn-fluorines (major isomers). These data are also in good agreement with the reported chemical shifts for polyfluorinated tricyclononenoxetanes [14] and tricyclononenazacyclobutanes [15] containing fluorine and fluoroalkyl substituents at C-4 carbon.…”

“…(3)). The value of the coupling constant H-2/H-5 (J = 8.3 Hz) suggests cis-orientation of two protons [14,15]. Proton H-5 in 7a is also coupled to F-4 (J 3 H-2ÀF-4 = 26.8 Hz, Table 1).…”

Reaction of quadricyclane with fluorinated sulfur-containing compounds

“…The formation of two isomers is the result of the different orientation of fluoroalkyl groups relative to the one-carbon bridge of the norbornene system. Based on steric considerations, it is reasonable to believe that in the major isomer the smaller CF 3 is located in syn and the bulkier C 2 F 5 group, respectively, in anti position, which is consistent with the orientation of substituents observed earlier in polyfluorinated 3-oxa- [7] and 3-aza- [8] tricyclo [4.2.1.0 2,5 ]non-7-enes.…”

“…(8)). (8) Upon standing of the mixture 13a,b, at ambient temperature, the major isomer 13a crystallized out (NMR), and its structure was confirmed by single crystal X-ray diffraction (see Fig. 2).…”

“…Recently, we have demonstrated that electron-deficient polyfluorinated carbonyl [7], nitrogen-containing compounds [8] and fluoroolefins [9] readily undergo thermal [2 + 2 + 2] cycloaddition to quadricyclane. The present study was aimed to develop the synthesis of polyfluorinated sulfur-containing polycyclic hydrocarbons based on reactions of quadricyclane.…”