Synthetic Chemistry of Quadricyclane

Hexafluorothioacetone based synthesis of fluorinated heterocycles

“…(1Z,5Z)-Cycloocta-1,5-diene (12) in reaction with 1 produced 13 as a result of insertion of two molecules of HFTA. In this case quite slow reaction (Eq.…”

“…In recent years it was demonstrated that readily available 1 [5,6] treated with alkali metal fluoride in polar solvent generates HFTA which can be subsequently trapped by a variety of electron-rich dienes [7][8][9][10][11]. Quadricyclane, which is known to have high reactivity towards electron deficient unsaturated hydrocarbons [12] and polyfluorinated materials [13][14][15][16], was reported recently to undergo cycloaddition with HTFA, producing 3-thia-4,4-bis(trifluoromethyl)tricyclo[5.2.1.0 2,5 ]non-7-ene [17]. This paper, reports new data on cycloaddition reactions of generated in situ HFTA with a variety of electron-rich dienes, and cyclic polyenes.…”

Kinetics and thermochemistry of the [2π+2σ+2σ]‐cycloaddition of quadricyclane with 2,3‐dicyano‐1,4‐benzoquinone

“…The unusual combination of the high strain energy (328 kJ⋅mol −1 ) 1 of quadricyclane ( 2 ) (tetracyclo[3.2.0.0 2,7 0 4,6 ]heptane) and its high thermal stability ( k dec. = 9.6 × 10 −6 s −1 at 140 о С) 2 has attracted the attention of researchers. A large amount of data on the synthesis of [2π+2σ+2σ] adducts of quadricyclane with a wide range of dienophiles have been accumulated, ─ but only few quantitative kinetic and thermochemical measurements were carried out for the reactions involving 2 and no data were available for the reactions involving 1 . Quadricyclane has a low ionization potential (7.40 eV), which promotes the fast formation of adducts with strong π‐acceptor dienophiles in the cycloaddition reactions .…”

“…For 2,3‐dicyano‐1,4‐benzoquinone, a high π‐acceptor property should be expected. A huge difference in the enthalpy of C 7 H 8 isomers formation, quadricyclane (339.1), norbornadiene (247.6), and cycloheptatriene (183.7 kJ⋅mol −1 ), indicate an increased strain energy in quadricyclane, which should be released significantly by opening of two cyclopropane moieties in 2 during the adduct formation. This is the reason of a record enthalpy of the reactions of 2 with tetracyanoethylene ( 5 ) (–236.1) and with 4‐phenyl‐1,2,4‐triazoline‐3,5‐dione ( 8 ) (–255.1 kJ⋅mol −1 ) in comparison with all known cycloaddition reactions .…”

Isomerization of Norbornadiene to Quadricyclane Using Ti-Containing MCM-41 as Photocatalysts

“…The sensitizer-catalytic isomerization has been widely investigated. Many sensitizers like Michler's Ketones, benzenzophenone, CuCl 2 and Ru compounds have been used for this reaction [7][8][9]. Although these sensitizers show high activity and selectivity, they, unfortunately, suffer from some drawbacks.…”