Friedel-Crafts Reaction Promoted by Hexameric Resorcinarene Capsule

In the last years, hydrogen-bonded hexameric capsules of resorcinarenes have been intensively investigated as nanoreactors in catalysis. In particular, their ability to stabilize cationic reactive intermediates and to create an unique nanoenvironment has been exploited for a series of chemical reactions ranging from terpene cyclization to carbonyl-olefin metathesis. In this communication, we will show that the bridged water molecules of the resorcinarene capsule are able to activate the C-Cl bond of benzyl chloride by H-bonding interaction, in order to promote a mild Friedel-Crafts benzylation of several arenes and heteroarenes. Moreover, we will show that the self-assembled capsule is able to exert a supramolecular control on the reaction outcome, as evidenced by the unusual benzylation at the -position of N-methylpyrrole and by the altered nucleophile reactivity, which is determined by their affinity for the inner cavity of the capsule rather than by their nucleophilicity