Orthogonal functionalization of a fullerene building block through copper-catalyzed alkyne-azide and thiol-maleimide click reactions

In this study, the synthesis of an orthogonally clickable fullerene building block mono-adduct bearing on one side an alkyne unit and a maleimide moiety on the other side is presented. This derivative has been involved in CuAAC and thiol-maleimide click reactions using stepwise or one-pot processes with benzyl azide and 1-octanethiol. The one-pot process involving the CuAAC reaction followed by the thiol-maleimide conjugation gives the highest yield. This new platform could pave the way for the synthesis of a wide range of fullerene derivatives exploiting this set of orthogonal reactions.