Catalytic Condensation of Primary Nitro Compounds with Dipolarophiles: Functionalisation of [60]Fullerene.

We have thoroughly investigated a new general procedure for the synthesis of 4,5-dihydroisoxazoles by catalysed condensation of primary nitro compounds with olefins This protocol, in one single pot, avoids the use of dehydrating reagents and formation of by-products derived from them. These condensations have been successfully carried out, using appropriate catalysts, either in chloroform or in ethanol or in water. The condensation is applicable to a wide range of functionalised dipolarophiles with good to excellent yields. Reactions with electron-poor dipolarophiles lead to either condensation to isoxazolines or to conjugate addition products, depending on the nitro compound (e.g. ethyl nitroacetate) and catalyst: the presence of copper (II) in the catalytic system selectively favours condensation . The application of this protocol to a peculiar electron-poor dipolarophile such as [60]fullerene will be presented. [60]Fullerene reveals a yet unexploited reactivity towards nitro compounds which may be useful for its functionalisation possibly extended to carbon nanotubes.