Stereoselective Insertion of Formamides into the C−Si Bond of Siliranes

Stereochemistry of cycloaddition of (S)-N-(1-phenylethyl)-C-diethoxyphosphorylated nitrone with vinyl acetate. Studies on mutarotation of 3-(O,O-diethylphosphoryl)-5-hydroxyisoxazolidines

“…Removal of the acetyl group in 9 would lead to 5-hydroxyisoxazolidine derivative 10 for which mutarotation is expected, as noticed earlier for structurally similar isoxazolidines, 14,36-41 isoxazolines 42 as well as other compounds possessing cyclic hemiacetal or hemiketal moiety (e.g., hydroxylated oxasilacyclopentane derivatives). [43][44][45][46][47] To this end, the acetyl groups in the enantiomerically pure isoxazolidines 9 were subjected to ammonolysis.…”

ZnBr2-Catalyzed Insertions of Carbonyl Compounds into Silacyclopropanes: Regiochemical Reversal Dependent on Metal Salt

“…The observed regiochemistry and carbonyl reactivity was rationalized by consideration of organometallic species 3 (Scheme ) which is believed to form upon transmetalation of the more substituted C−Si bond to copper. We have obtained selectively products with this 1,2‐regiochemistry for all insertion reactions of silacyclopropanes thus far 2–4…”

Silver‐Catalyzed Silylene Transfer

“…After acetolysis, the resulting oxasilacyclopentane (73) participated in a nucleophilic substitution reaction with silyl enol ether 74 to produce ethyl ketone 72 diastereoselectively. 62,[78][79][80] After protection of the ketone, the hindered C--Si bond was oxidized using conditions developed by Woerpel and coworkers to afford 75. 66,81,82 The resulting polypropionate fragment was elaborated in 10 steps to 1 0 -epi-stegobinone.…”