Diels-Alder via Molecular Recognition in a Crystalline Molecular Flask

In the pore of a porous coordination network, Diels-Alder reactants, a diene and a dienophile, are recognized by donor-acceptor and multiple H-bond interactions, respectively, and fixed at ideal positions for the reaction. Heating the crystals promoted the Diels-Alder reactions with enhanced reactivity and controlled regioselectivity as clearly monitored by in situ X-ray crystallography.