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Silicon Tetrakis(trifluoromethanesulfonate): A Simple Neutral Silane Acting as a Soft and Hard Lewis Superacid.

ABSTRACT: A facile synthesis and isolation of pristine silicon tetrakis(trifluoromethanesulfonate), Si(OTf)₄ , is reported, acting as the first neutral silicon-based Lewis superacid suitable towards soft and hard Lewis bases. Its OTf groups have a dual function: they are excellent leaving groups and modulate the degree of reactivity towards soft and hard Lewis bases. Exposed to soft Lewis donors, Si(OTf)₄ leads to [L₂ Si(OTf)₄ ] complexes (L=isocyanide, thioether and carbonyl compounds) with retention of all Si-OTf bonds. In contrast, it can cleave C-X bonds (X=F, Cl) of hard organic Lewis bases with a high tendency to form SiX₄ (X=F, Cl) after halide/triflate exchange. Most notable, Si(OTf)₄ allows a gentle oxydefluorination of mono- and bis(trifluoromethyl)benzenes, resulting in the formation of the corresponding benzoylium species, which are stabilized by the weakly coordinating [Si(OTf)₆ ] dianion.

SUBMITTER: Hermannsdorfer A

PROVIDER: S-EPMC8252640 | biostudies-literature | 2021 Jun

REPOSITORIES: biostudies-literature

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Silicon Tetrakis(trifluoromethanesulfonate): A Simple Neutral Silane Acting as a Soft and Hard Lewis Superacid.

Hermannsdorfer André A Driess Matthias M

Angewandte Chemie (International ed. in English) 20210505 24

A facile synthesis and isolation of pristine silicon tetrakis(trifluoromethanesulfonate), Si(OTf)4 , is reported, acting as the first neutral silicon-based Lewis superacid suitable towards soft and hard Lewis bases. Its OTf groups have a dual function: they are excellent leaving groups and modulate the degree of reactivity towards soft and hard Lewis bases. Exposed to soft Lewis donors, Si(OTf)4 leads to [L2 Si(OTf)4 ] complexes (L=isocyanide, thioethe ...[more]

PMID: 33826216

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