Modulation of Reactivities of Dienophiles for DielsAlder Reactions via Complexation of α,β-Unsaturated Chelating Amides

We describe the modulation of reactivities of dienophiles for DielsAlder reactions via a new principle based on chelating amides positioned adjacent to their CC bond. It is demonstrated for modified acrylic acid derivatives and related dienophiles with three different chelating entities. Complexation of the chelators leads to an intensified electron-withdrawing effect leading to an enhancement of reactivity in DielsAlder reactions depending on the complexed metal ion. The application of this new approach might be extended to other reactions with reacting entities adjacent to chelating amides.