Ruthenium-Catalyzed Nucleophilic Allylic Substitution Reactions from β-Silylated Allylic Carbonates

The trans addition of HSiEt3 to propargylic ethyl carbonates catalyzed by the ruthenium complex [Ru(C5Me5)(MeCN)3][PF6], 1, leads to H2CC(SiEt3)CH(R)OCO2Et (R = H, Me, Prn, or Ph) derivatives as allylic substrates for subsequent ruthenium-catalyzed nucleophilic allylic substitution reactions. Ruthenium catalysts based on a [Ru(C5Me5)(2-quinolinecarboxylato)] or [Ru(C5Me5)(2,2′-bipyridine)]+ fragment are more efficient than 1 for access to various H2CC(SiEt3)CH(R)Nu-functionalized vinylsilanes (R = H, Me; NuH = secondary amine, phenol, dimethylmalonate, methanol). New [Ru(C5Me5)(2-quinolinecarboxylato)(η3-allyl)]+ cationic ruthenium(IV) intermediates are characterized, and experiments using a deuterium-labeled allylic carbonate provide evidence for a regioselectivity arising from the presence of the 2-quinolinecarboxylato (N,O)-chelate.