Silylative coupling of vinyl alkyl ethers with vinylsilanes catalyzed by ruthenium complexes

Ruthenium complexes such as RuHCl(CO)(PPh3)(3) (I), RuCl(SiMe3)(Co)(PPh3)(2) (II), RuCl2- (PPh3)(3) (III), and Ru(CO)(3)(PPh3)(2) (IV) appear to be very effective catalysts of cross-disproportionation of vinyl-trisubstituted silanes CH2=CHSiR3 (where R-3 = Me-3, PhMe2, (OEt)(3)) with vinyl alkyl ethers CH2=CHOR' (where R' = ethyl, n-propyl, n-butyl, tert-butyl, tert-pentyl, 2-ethylhexyl, cyclohexyl, trimethylsilyl) to yield a mixture (E+Z) of 1-silyl-2-alkoxyethenes. Stoichiometric insertion of vinyl n-propyl ether into Ru-Si bonds of II and MS study of the products of the deuterated vinyltrimethylsilane with vinyl ethyl ether indicate that the mechanism of cross-disproportionation involves a migratory insertion of the vinyl ether into the Ru-Si bond (and vinylsilane into the Ru-H bond) followed by beta-H (and P-Si) transfer to eliminate 1-triorganosilyl-2-alkoxyethenes (and ethene).