Exothermic isomerization of water-soluble quadricyclanes to norbornadienes by soluble and insoluble catalysts
Abstract
Water-soluble quadricyclane derivatives (1) were stable in an aqueous sodium carbonate solution, but addition of a catalytic amount of water-soluble cobalt porphyrin complexes (3) induced rapid and quantitative isomerization of (1) to norbornadiene derivatives (2) under release of heat. Insoluble catalysts (4) prepared by adsorption of Co-TPP or Co-Pc on activated carbon were similarly active as the soluble analogues. They were stable enough to keep high activities for recycling use.