Ruthenium-Catalyzed C-H Bond Activation of Michael Acceptors: An Unusual Reactivity Leading to Allylsilanes

We report here an improved catalyst for the functionalization of Michael acceptors, involving C-C bond formation via C-H bond activation, using an in situ generated ruthenium active species. Moreover, on some particular substrates, the C-H functionalization resulted unexpectedly in the formation of allylsilanes rather than in the expected conjugated adducts, affording a new straightforward methodology to access useful stereodefined trisubstituted allylsilanes via C-H bond activation. Preliminary results have shown that they were reactive in the allylation of aldehydes, providing an access to alcohols bearing a quaternary carbon center.