Among concerted cycloadditions,t he Diels-Alder reaction is the grand old classic,which is usually achieved with acid catalysis.I nt his report, hydroxypyrones,o xa-, and thiazolones are explored because they provide access to anionic dienes.T heir [4+ +2] cycloaddition with cyclic and acyclic dienophiles,such as maleimides and fumarates,affords bicyclic products with four new stereogenic centers.B ifunctional anion-p catalysts composed of amine bases next to the p surface of naphthalenediimides (NDIs) are shown to selectively stabilizet he "open", fully accessible anionic exo transition state on the p-acidic aromatic surface.O ur results also include reactivities that are hard to access with conventional organocatalysts,s uch as the exo-specific and highly enantioselective Diels-Alder reaction of thiazolones and maleimides with complete suppression of the otherwise dominant Michael addition. With increasing p acidity of the anionp catalysts,t he rates,c hemo-, diastereo-, and enantioselectivities increase consistently.