SiO2 Nanoparticles catalyzed Synthesis of alkyl 2-dinaphtho[2,1-d:1,2-f][1,3]- dioxepin-2-ylacetate from stabilized phosphorus ylides

Protonation of the highly reactive 1:1 intermediates, produced in the reaction of triphenylphosphine and alkyl acetylenecarboxylates, by 1,1-binaphthyl-2,2 -diol leads to vinyltriphenylphosphonium salts, which undergo Michael addition reaction to produce the corresponding stabilized phosphonium ylides. SiO2 Nanoparticles was found to catalyze the conversion of the stabilized phosphonium ylides to alkyl 2-dinaphtho[2,1-d:1,2-f][1,3]- dioxepin-2-ylacetate under solvent-free conditions using microwave (0.18 KW, 0.5 min) and thermal (70 0C, 30 min) conditions.