Université de Fribourg

Regioselective oxidative ring opening of cyclopropyl silyl ethers: a quantum chemical study

Rinderhagen, Heiko ; Mattay, Jochen ; Nussbaum, Rafael ; Bally, Thomas

In: Chemistry, a European Journal, 2010, vol. 16, no. 24, p. 7121–7124

In contrast to the structurally and configurationally stable alkyl- or aryl-substituted cyclopropyl radical cations, cyclopropyl silyl ethers undergo spontaneous ring opening upon oxidation whereby the endocyclic C-C(O-TMS) bond is cleaved with remarkable selectivity. DFT calculations on 1-trimethylsilyloxybicyclo[4.1.0]heptane show that this selectivity arises from the topology of the potential...

Université de Fribourg

Oxidative rearrangements of tricyclic vinylcyclobutane derivatives

Grota, Juliane ; Mattay, Jochen ; Piech, Krzysztof ; Bally, Thomas

In: Chemistry - A European Journal, 2006, vol. 12(17), p. 4559-4567

Three tricyclic vinylcyclobutanes (3-methylenetricyclo[5.3.0.02,6]decanes 1-3) have been subjected to ionization by photoinduced electron transfer in solution and by X-irradiation in Ar matrices. All three compounds undergo oxidative cycloreversion; the cleavage of the four-membered ring, however, occurs in a different direction depending on the presence of a methyl group...

Université de Fribourg

Radical Cations of Phenyl-Substituted Aziridines: What Are the Conditions for Ring Opening ?

Gaebert, Carsten ; Mattay, Jochen ; Toubartz, Marion ; Steenken, Steen ; Müller, Beat ; Bally, Thomas

In: Chemistry - A European Journal, 2005, vol. 11(4), p. 1294-1304

Radical cations were generated from different phenyl-substituted aziridines by pulse radiolysis in aqueous solution containing TlOH.+, N₃. or SO₄.- as oxidants or in n-butyl chloride, by ⁶⁰Co γ radiolysis in Freon matrices at 77 K, and in some cases by flash photolysis in aqueous solution. Depending on the substitution pattern of the aziridines, two...