Mechanistic change in acid-catalyzed hydrolysis of silyl vinyl ethers

Photoinduced electron transfer from enol silyl ethers to quinone. Part 2. Direct observation of ion-pair dynamics by time-resolved spectroscopy

“…Although the relative rates of desilylation for the various R,Si-substituted cation radicals is not known, tertbutyldimethylsilyl-and triphenylsilyl-substituted enol ethers are much more stable to acidic hydrolysis than their trimethylsilylated analogues. 75 If the same trend applies to the solvolytic loss of R,Si+ in Scheme 4, the cation radicals 5" and 6" are expected to react more slowly than 2" The reduced rates of desilylation for these radicals will allow the reformation of the contact radical ion pair as in eqn. (10) enhance ion-pair collapse and enone formation according to Schemes 2 and 3.…”

o-Carboranylcarbene and m-carboranylcarbene

“…It was allowed to warm up to room temperature and stand for 4 h. The solvent was stripped, and the residue was extracted with ether, washed with brine, and dried over sodium sulfate. Evaporation of the ether and sublimation yielded 1-formyl-o-carborane (1.32 ), 4.05 (br s, carborane H); IR (CHC13) 3060, 2580, 1745 cm"1.…”

“…Thus in this case, but not all others, reactive nitrogen-containing intermediates derived from phenyldiazomethane can be eliminated. 4 We wondered if the stability conferred by a phenyl group upon an adjacent divalent carbon would be duplicated by a carborane. Would the effect of "two-dimensional" aromaticity be resembled by those of the "three-dimensional" or "super aromaticity" of the carboranes?…”

Chemoselective Ruthenium‐Catalyzed Reduction of Acid Chlorides to Aldehydes with Dimethylphenylsilane

“…The reduction of some substrates containing α‐protons resulted in the formation of a mixture of target aldehydes and silyl enols (e.g., entries 2 and 7). But the latter compounds can be easily converted into aldehydes by a simple aqueous work‐up 19…”