Solventless Silane Alcoholysis Catalyzed by Recoverable Dirhodium(II) Perfluorocarboxylates

We have developed a novel reaction protocol for the highly efficient and sustainable catalysis of the silane alcoholysis reaction. The catalysts of choice are dirhodium(II) perfluorocarboxylates bearing long perfluoroalkyl chains, which are easily prepared in one step from commercial precursors. Under optimized reaction conditions, these catalysts exhibit up to about 50 times higher activity and 100 times higher productivity than analogous dirhodium(II) complexes described in the prior art. Furthermore, the reaction can be run in a completely solventless fashion. Finally, heterogenization of these catalysts has been accomplished through a novel strategy based on fluorous chemistry. Indeed, perfluorinated catalysts of this kind are easily adsorbed on silica which has been previously functionalized at its surface with perfluoroalkyl chains. Use of such supported catalysts (bonded fluorous phase catalysts) allows an easy and almost complete catalyst separation and recycling with improved catalytic performance.