Supramolecular Subphthalocyanine Cage as Catalytic Container for the Functionalization of Fullerenes in Water.

Herein we report the first example of a supramolecular cage that works as a catalytic molecular reactor to perform transformations over fullerenes in aqueous medium. Taking advantage of the ability of metallo-organic Pd(II)-subphthalocyanine (SubPc) capsules to form stable host:guest complexes with C60, we have prepared a water-soluble cage that provides a hydrophobic environment for conducting cycloadditions over encapsulated C60, namely, Diels-Alder reactions with anthracene. Indeed, the presence of catalytic amounts of solubilized SubPc cage promotes co-encapsulation of insoluble C60 and anthracene substrates, allowing the reaction to occur inside the cavity under mild conditions. The lower stability of the host:guest complex with the C60 cycloadduct facilitates displacement by pristine C60, allowing catalytic turnover. Moreover, bis-addition compounds are regioselectively formed inside the cage when using excess anthracene.