Supramolecular masks for the regioselective synthesis of Diels-Alder hetero-tris-adduct C60 fullerene

Abstract

Herein, we report the regioselective hetero-tris-functionalization of fullerenes via a sequential Diels-Alder cycloaddition strategy. The first addend is introduced onto C60 through a cascade process involving a Ru-catalyzed cycloisomerization of 1,6-enynes, followed by a Diels-Alder reaction with C₆₀. Subsequently, supramolecular nanocapsules are employed as regioselective masks, enabling enhanced control over the formation of a hetero-tris-adduct bearing two pentacene units.These units are positioned equatorially with respect to the initial addend and adopt a trans-1 relative orientation. Notably, a single pure tris-regioisomer, e,e,t1(I), is obtained for both 2a-Pn₂ and 2d-Pn₂. Access to pure-isomer hetero-tris Diels-Alder adducts is unprecedented and highlights the broad potential of the supramolecular mask strategy.