Synthesis of Chiral Polyethers Containing Imidazolidinone Repeating Units and Application as Catalyst in Asymmetric Diels-Alder Reaction

In this study, enantiopure imidazolidinones containing two hydroxyphenyl groups were synthesized, and the Williamson synthesis of the chiral bisphenols thus prepared with dihalides afforded polyethers containing chiral imidazolidinone repeating units. These chiral imidazolidinone polyethers exhibited excellent catalytic activity in the asymmetric Diels–Alder reaction. With the use of these polymeric catalysts, enantioselectivities up to 99% were obtained, higher than those obtained by the corresponding monomeric imidazolidinone catalyst in homogeneous solution. The polymeric catalysts were found to be insoluble in commonly used organic solvents, and they could be repeatedly used without the loss of activity.