Silyl enol ethers, dehydrosilylation

The thermal C3 -> 5 ring expansion of 1-siloxy-l-vinylcyclopropanes occurs either from the Z or from the E isomers. It leads to cyclopentanone silyl enol ethers that are able to undergo either further regiospecific alkylation into 2,3-disubstituted cyclopenta-nones 145.209,213 dehydrosilylation into cyclopentenones The overall process constitutes an efficient three-carbon annelation process (equation 129). 

By Saegusa-Ito oxidation " Dehydrosilylation of silyl enol ethers with... 

Ito, Y., Hirao, T., Saegusa, T. Synthesis of a,P-unsaturated carbonyl compounds by palladium(ll)-catalyzed dehydrosilylation of silyl enol ethers. J. Org. Chem. 1978, 43, 1011-1013. 

Ito Y, Toshikazu H, Saegusa T (1978) Synthesis of a, 3-Unsaturated Carbonyl Compoimds by Palladium(II)-catalyzed Dehydrosilylation of Silyl Enol Ethers. J Org Chem 43 1011... 

Synthetically usefiil Pd(ll)-catalyzed oxidation of ketones and aldehydes is presented by regioselective synthesis of a,/3-unsaturated carbonyl compounds via their silyl enol ethers. The Pd(II)-catalyzed dehydrosilylation for regioselective preparation of a,/S-unsaturated carbonyl compounds is carried out simply by treatment with Pd(ll)(OAc)2 of silyl enol... 

The palladium(n) induced dehydrosilylation of silyl enol ether may involve an oxa-ir-allylpalladium(II) intermediate, which subsequently undergoes /3-elimination of palladium hydride to furnish a,/S-unsaturated ketone or aldehyde (Scheme 5). 

Dehydrosilylation of silyl enol ethers prepared from unsymmetrical polyfunctional-ized ketones gives the corresponding acyclic and five-,f f seven-,t t ... 

Dehydrosilylation coupled with miscellaneous synthesis of silyl enol ethers via rearrangement of 1-siloxy-l-alkenylcyclopropane/ reactions of y-siloxyaUylmetals with elec-trophiles/ and rearrangement of a-silylketones gives the corresponding ketones. 

Bockman, T.M., Perrier, S., and Kochi, J.K., Dehydrosilylation versus a-couphng in the electron-transfer of silyl enol ethers to quinones. Strong effect on photogenerated ion pairs, /. Chem. Soc., Perkin Trans. 2, 595,1993. 

Dehydrosilylation versus oxidative addition of enol silyl ethers to quinones... 

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