Fullerene as a Platform for Recyclable TEMPO Organocatalysts for the Oxidation of Alcohols

Abstract

[60]Fullerene has been employed successfully as a molecular platform to anchor 12 2,2,6,6-tetramethylpiperidine-1-oxyl(TEMPO) moieties. Such an octahedrally substituted C60-derivative has been employed as an organocatalyst for the oxidation of primary and secondary alcohols using the Anelli protocol. The reaction showed a general applicability to various alcohols, and the catalyst was recovered easily and could be recycled for at least seven cycles with no loss in catalytic activity. EPR spectroscopy studies revealed that the amount of radicals decreases during the catalytic cycles, even if the recovered material still displays unchanged catalytic activity. This new approach paves the way to use fullerene as a molecular platform to support other kinds of organometallic and organocatalysts as well as for their use as model compounds to understand the behavior of other nanocarbon-supported catalysts.