Immobilized cyclopentadiene in the Diels Alder/retro-Diels Alder concept

Abstract

Immobilized cyclopentadiene on polystyrene has been synthesized and studied in [4π + 2π]-cycloadditions with a variety of dienophiles. Reasonable to excellent conversions were obtained. The cyclopentadiene Diels-Alder adducts turned out to be generally too stable to allow effective cycloreversion both under dynamic (under vacuum) and static (in a solvent) thermal conditions. A detailed study of the immobilized cyclopentadiene benzoquinone adduct showed a remarkable inreactivity of the enone double bond showing the limitations of the solid phase approach in the Diels-Alder/Retro-Diels-Alder synthetic strategy.