New synthons of formylanion (methoxy(trimethylsilyl)methane (1)) and alkoxylcarbonyl anion (methoxybis(trimethylsilyl)methane (2)) have been developed using oxidative cleavage of the carbon-silicon bond by anodic oxidation.
The stereocontrolled synthesis of new carbohydrate-derived acylsilanes with the silylcarbonyl moiety linked to the anomeric carbon via a methylene group is described. Reaction of these acylsilanes with perfluoroorganometallic reagents followed by treatment with hydrazines or amidines led to new polyfluorinated homo-C-nucleoside analogues, in a one-pot or two-step transformation, respectively.
Phenylthio(trimethylsilyl)methane, phenylthiosbis(trimethylsily)methane, methoxy(trimethysily)methane, and methoxybis(trimethylsilyl)methane are depronated and the resulting anions are alkylated with electrophiles such as organic halides. The alkylation products are readily converted into the corresponding dimethyl acetals or methyl esters by electrochemical oxidation in methanol.
A new method for the synthesis of acylsilanes via one-carbon homologation of aldehydes
The first vertical ionization energies of dialkylethers are lowered up to 3 eV (!) by beta-trimethylsilyl substituents and, therefore, further confirm the powerful electron donor effect of -CH3-n[Si(CH3)3]n and -Si[Si(CH3)3]3 groups. The gas-phase photoelectron spectra are assigned based on geometry-optimized MNDO calculations and the substituent effects are discussed in terms of conformationally dependent hyperconjugative second order perturbations.