Nucleophilic tetrafluoroethylation of carbonyl compounds with fluorinated sulfones

Advances in the Synthesis and Application of Tetrafluoroethylene‐ and 1,1,2,2‐Tetrafluoroethyl‐Containing Compounds

“…The reaction with a ketone (acetophenone) was unfruitful and reactions with an acyl chloride or ester also did not give any product. This is in a good agreement with our results acquired with the triethylsilane derivative of fluorinated sulfone ( 105b′ ) which yielded only 22 % of the product of reaction with 2‐naphthaldehyde compared to 56 % achieved with 105b under identical conditions (Scheme b) . The observed decreased reactivity was corroborated by a short computational study, which showed higher atomic charges on the CF 2 ‐carbon next to the triethylsilyl group, and therefore lower nucleophilicity compared to both 105a and 105b .…”

“…Additionally, silane 105a can easily be oxidized to fluorinated sulfone PhSO 2 CF 2 CF 2 SiMe 3 ( 105b ) using m ‐chloroperoxybenzoic acid (mCPBA), which also undergoes nucleophilic additions to aldehydes, reactive ketones and enamines (Scheme ) , . The lower nucleophilicity of 105b compared to 105a caused further decrease in the product yields.…”

“…The lower nucleophilicity of 105b compared to 105a caused further decrease in the product yields. In the case of the carbonyl compounds, the authors showed that the nucleophilicity was related to the calculated charges on the silylated carbon atom: lower values of the atomic charge in 105a corresponded to its higher nucleophilicity and vice versa for 105b …”

“…Additionally, silane 105a can easily be oxidized to fluorinated sulfone PhSO 2 CF 2 CF 2 SiMe 3 (105b) using m-chloroperoxybenzoic acid (mCPBA), which also undergoes nucleophilic additions to aldehydes, reactive ketones and enamines (Scheme 63). [148,149] The lower nucleophilicity of 105b compared to 105a caused further decrease in the product yields. In the case of the carbonyl compounds, the authors showed that the nucleophilicity was related to the calculated charges on the silylated carbon atom: lower values of the atomic charge in 105a corresponded to its higher nucleophilicity and vice versa for 105b.…”

“…In the case of the carbonyl compounds, the authors showed that the nucleophilicity was related to the calculated charges on the silylated carbon atom: lower values of the atomic charge in 105a corresponded to its higher nucleophilicity and vice versa for 105b. [149] Furthermore, Petko and co-workers showed that silyl reagents derived from tetrafluoroethyl-substituted azoles can be Scheme 63. Reactivity of fluorinated sulfone 105b towards carbonyl compounds and enamines.…”