Nucleophilic tetrafluoroethylation of carbonyl compounds with fluorinated sulfones
摘要:
Global interest in the "CF2CF2" building blocks (tetrafluoroethylene, tetrafluoroethyl) is still rather marginal. One of the main reasons is the lack of efficient and selective tetrafluoroethylation reagents. In this context, we present here three new reagents (PhSO2CF2CF2R, R = SiMe3, SiEt3 and H) capable of nucleophilic addition to carbonyl compounds, thus affording rare alcohols containing the CF2CF2 motif. The experimental observations are complemented with a brief computational study which confirmed that the reactivity of the nudeophilic reagents is strongly dependent on electronic properties of substituents on both ends of the CF2CF2 group. (C) 2014 Elsevier B.V. All rights reserved.
Development of PhSCF2CF2SiMe3 as a Tandem Anion and Radical Tetrafluoroethylene Equivalent: Preparation of Tetrafluoroethyl-Substituted Alcohols and Tetrafluorotetrahydropyrans
PhSCF2CF2SiMe3 (1) was developed as a tandem anion and radical tetrafluoroethylene equivalent for the introduction of a CF2CF2 moiety. Fluoride-initiated nucleophilic additions of 1 to carbonyl compounds provide the corresponding alcohol adducts 2. Reduction of 2 gives tetafluoroethyl-containing alcohols 3, whereas 6-exo radical cyclizations of allyl ethers 4 yield tetrafluorotetrahydropyrans 5.