Multi-addition on nano-encapsulated fullerene derivatives bearing one functional group: Impact of the initial moiety

Fullerene multi-adducts have drawn significant research interest due to their remarkable properties, which often surpass those of mono-adducts across various applications. However, achieving regioselective synthesis of these multi-adducts remains challenging. Notably, the regioselective multi-functionalization of a malonate cyclopropane fullerene monoadduct has already been demonstrated, yielding a single tetra-addition pattern through a supramolecular mask strategy. In this study, we explore how the nature of the existing functional groups influences the Bingel multi-addition reaction of diethyl bromomalonate on different mono-functionalized fullerenes. To investigate this, we synthesized fullerene derivatives bearing either long, flexible chains, or a rigid dibenzodioxin moiety via the corresponding Diels–Alder reaction of o -dibromomethyl arenes with C 60 . These derivatives were then encapsulated within a supramolecular cage and subjected to multi-functionalization conditions. We monitored the reaction’s progress and final products using high-resolution mass spectrometry (HRMS), UV-Vis, and 1 H-NMR spectroscopy. These studies show that derivatives bearing different initial functionalities exhibit distinct multi-functionalization outcomes. We provide a detailed rationalization of the experimental observations. • Fullerene multi-adducts can be regioselectively synthesized via cage encapsulation of mono-adducts. • Only fullerene mono-adducts bearing small substituents have been used so far. • Fullerene derivatives, carrying long flexible or rigid polyaromatic substituents are synthesized. • Their further multi-derivatization, via supramolecular cage encapsulation, is investigated. • The nature of initial functional group dictates the multi-functionalization outcome.