Nano-organocatalysts synthesis: Boc vs Fmoc protection

We report the elaboration of new l-Proline functionalized superparamagnetic iron oxide nanoparticles that can act as a new enantioselective organocatalyst. Boc-l-Proline and Fmoc-l-Proline are grafted using two different methodologies on a nanoplateform constituted of 10 nm maghemite (γ-Fe2O3) nanoparticle stabilized by bidendate coating agent Alendronate. We show that coupling is far more efficient using microwave assisted methodology and that only Fmoc deprotection is compatible with our nanoplatform. Moreover the fluorenyl group is used for indirect quantification of grafted Proline onto nanoparticles.