Phenyl(trimethylsilyl)ketene. Some ketene reactions with diazomethane

Inversion of Stereochemistry in the Co2(CO)8-Catalyzed Carbonylation of Aziridines to β-Lactams. The First Synthesis of Highly Strained trans-Bicyclic β-Lactams

“…trans -1-(1,1-Dimethylethyl)-3,4-diphenyl-2-azetidinone (9b) : white solid, mp = 91−92 °C. 1 H-NMR (200 MHz) δ 1.33 ppm (s, 9H), 3.98 (d, 1H, J = 2.15 Hz), 4.48 (d, 1H, J = 2.15 Hz), 7.35 (m, 10H).…”

Oligomerization of Silyl Ketene: Favoring Chain Extension over Backbiting

“…Unfortunately, the propensity of alkyl and aryl ketenes to undergo dimerization and nucleophilic and electrophilic attack renders them unattractive as monomers. − As such, our group has focused on silyl ketenes; not only can these molecules be prepared on the gram scale and stored under common conditions because of the stability provided by the β-silicon effect (i.e., hyperconjugation) but the trialkyl silyl group also provides solubility and tunable steric demands. Reactions of silyl ketenes are relatively few: they can react with diazomethanes to form cyclopropanones and cyclobutanones or undergo [2 + 2] cycloaddition with aliphatic aldehydes in the presence of a Lewis acid, forming β-lactones . Alternatively, hydration of silylketenes has been used to prepare the corresponding α-silylated carboxylic acids, and α-silylated esters have been prepared by reaction of silyl ketenes with alcohols in the presence of ZnX 2 (X = Cl, I) …”

Synthesis of highly substituted allenylsilanes by alkylidenation of silylketenes

“…A second impediment to the generalisation of the approach has been the paucity of methods for preparing substituted silylketenes. [ 18 , 19 ] Methods based upon the thermolysis of siloxyalkynes [ 20 ] and dehydrohalogenation of substituted α-silyl acid halides [ 21 , 22 ] have not found general application. We recently reported a mild and functional group tolerant approach to substituted silylketenes based upon a rhodium-mediated formal Wolff rearrangement of silylated diazoketones.…”