13950-57-7Relevant academic research and scientific papers
Lewis Acid-Activated Reactions of Silyl Ketenes for the Preparation of α-Silyl Carbonyl Compounds
Mitchell, Sarah M.,Xiang, Yuanhui,Matthews, Rachael,Amburgey, Alexis M.,Pentzer, Emily B.
, (2019/11/14)
Silyl-substituted ketenes are attractive molecular building blocks due to their stability and ease of storage, as opposed to unstable alkyl and aryl ketenes. To better understand the reactivity of silyl ketenes and, in turn, their use in the preparation o
Lewis Acid-Activated Reactions of Silyl Ketenes for the Preparation of α-Silyl Carbonyl Compounds
Mitchell, Sarah M.,Xiang, Yuanhui,Matthews, Rachael,Amburgey, Alexis M.,Pentzer, Emily B.
, p. 14461 - 14468 (2019/12/02)
Silyl-substituted ketenes are attractive molecular building blocks due to their stability and ease of storage, as opposed to unstable alkyl and aryl ketenes. To better understand the reactivity of silyl ketenes and, in turn, their use in the preparation o
Silver-catalyzed silicon-hydrogen bond functionalization by carbene insertion
Iglesias, M. Jose,Nicasio, M. Carmen,Caballero, Ana,Perez, Pedro J.
, p. 1191 - 1195 (2013/02/23)
The catalytic functionalization of silicon-hydrogen bonds by means of the insertion of carbene units:CHCO2Et from ethyl diazoacetate (EDA) has been achieved using a silver-based catalyst, constituting the first example of this metal to promote this transformation. Competition experiments have revealed that the relative reactivity of substituted silanes depends on the bond dissociation energy of the Si-H bond (tertiary > secondary > primary for ethyl substituted). In the presence of bulky substituents such order reverts to secondary > primary ≈ tertiary (for phenyl substituted). Screening with other diazo compounds has shown that N2C(Ph)CO2Et displays similar reactivity to that of EDA, whereas other N2C(R)CO 2Et (R = Me, CO2Et) gave lower conversions. The Royal Society of Chemistry 2013.
Methyldiphenylsilylation of Ester and Lactone Enolates
Larson, Gerald L.,Maldonado, Veronica Cruz de,Fuentes, Lelia M.,Torres, Luz E.
, p. 633 - 639 (2007/10/02)
The reactions of a variety of ester and lactone enolates with methyldiphenylchlorosilane were studied.The C-versus O-silylation, leading to the α-silyl ester or lactone and silyl ketene acetal, respectively, was studied as a function of the structure of the ester or lactone and the reaction conditions.It was found that all simple acetates are C-silylated irrespective of the steric demands of the alcohol portion of the ester.Esters that are monosubstituted in the α-position are cleanly C-silylated with the notable exceptions of ethyl phenylacetate and ethyl phenoxyacetate, both of which give mixtures of C- and O-silylation.The α,α-disubstituted esters give only O-silylation, but the α,α-substituted α-silyl esters are readily prepared by the alkylation of the appropriate monosubstituted α-silylated ester.The reaction of the lithium enolate of ethyl acetate and tert-butyl acetate with (S)-(-)-1-naphthylphenylmethylchlorosilane showed the reaction to occur with inversion of configuration at silicon.Methylation of tert-butyl (1-naphthylphenylmethylsilyl)acetate gave a 91:9 mixture of diastereomeric α-silyl propionates, which could not be separated.It was found that only the γ-lactones gave C-silylation with δ-valerolactone and ε-caprolactone giving O-silylation.
Selective γ-Substitution of α,β-Unsaturated Esters via α-Trimethylsilyl β,γ-Unsaturated Esters
Albaugh-Robertson, Pamela,Katzenellenbogen, John A.
, p. 5288 - 5302 (2007/10/02)
In order to achieve selective γ-substitution of α,β-unsaturated esters, we investigated the directive effect of silicon in the reaction of various electrophiles with α-trimethylsilyl β,γ-unsaturated esters.These esters were prepared by nickel-catalyzed vinylation reactions of the lithium enolate of ethyl α-(trimethylsilyl)acetate.The α-silyl β,γ-unsaturated esters reacted with a variety of electrophiles (aldehydes, ketones, acetals, ketals, acid chlorides, and chloro thioethers) in the presence of Lewis acids (titanium tetrachloride and trimethylsilyl trifluoromethanesulfonate) to give exclusively the γ-substituted product in moderate to good yields.In some cases, the primary substitution products underwent additional conversions under the reaction conditions, such as the cyclization of the δ-hydroxyl or δ-keto enoates to dihydropyrones or pyrones, respectively.These α-silyl β,γ-unsaturated esters are effective reagents for achieving complete γ-selective substitution of α,β-unsaturated ester systems.
