67262-99-1Relevant articles and documents
Interaction of Trimethylsilyl and Trimethylstannyl Substituants with C-O Bonds at the γ Position. Results from X-ray Structural Studies and Solvolysis Studies
Green, Alison J.,Pigdon, Tracey,White, Jonathan M.,Yamen, Joseph
, p. 3943 - 3951 (2007/10/03)
Accurate X-ray structural studies have been carried on the γ-Me3M (M = Si, Sn)-substituted cyclohexyl esters 21-Ns, 22-Ns, 23-Ns, 21-PNB, and 24-PNB. Analysis of the structural parameters reveals that the C(alkyl)-O(ester) bond distance is lengthened slightly compared to nonmetal- substituted analogues provided that the C-M, C-O, and intervening C-C bonds are in the W arrangement as is the case for 22-Ns, 23-Ns, and 24-Ns. However, the C-O bond distances for 22-PNB and 22-Ns, which do not have the W geometry, are not significantly lengthened. These structural effects are consistent with the presence of a percaudel interaction between the back lobe of the C-M σ bond and the C-O σ* orbital. The γ-Me3Sn cyclohexyl nosylates 21-Ns and 23-Ns undergo unimolecular solvolysis in 97% TFE/H2O with relative rates ca. 1:>10 000.
The Conjugate Addition of a Silyl Group to Enones and its Removal with Copper(II) Bromide: A Protecting Group for the αβ-Unsaturation of αβ-Unsaturated Ketones
Ager, David J.,Fleming, Ian,Patel, Shailesh K.
, p. 2520 - 2526 (2007/10/02)
Silyl-lithium reagents mixed with copper(I) salts react with enones, including esters and aldehydes, to give β-silyl carbonyl compounds in good yield.The β-silylketones can be used in synthesis without risk to the silyl group and the enone group can be restored by bromination-desilylbromination with copper(II) bromide.The principle is illustrated with syntheses of carvone and dihydrojasmone.
