Synergistic Anion–(π) n –π Catalysis on π-Stacked Foldamers

In this report, we demonstrate that synergistic effects between π–π stacking and anion−π interactions in π-stacked foldamers provide access to unprecedented catalytic activity. To elaborate on anion–(π)n–π catalysis, we have designed, synthesized and evaluated a series of novel covalent oligomers with up to four face-to-face stacked naphthalenediimides (NDIs). NMR analysis including DOSY confirms folding into π stacks, cyclic voltammetry, steady-state and transient absorption spectroscopy the electronic communication within the π stacks. Catalytic activity, assessed by chemoselective catalysis of the intrinsically disfavored but biologically relevant addition reaction of malonate half thioesters to enolate acceptors, increases linearly with the length of the stacks to reach values that are otherwise beyond reach. This linear increase violates the sublinear power laws of oligomer chemistry. The comparison of catalytic activity with ratiometric changes in absorption and decreasing energy of the LUMO thus re...