Lewis Acidity of Bis(perfluorocatecholato)silane: Aldehyde Hydrosilylation Catalyzed by a Neutral Silicon Compound

Authors

Allegra L. Liberman-Martin, Chapman UniversityFollow
Robert G. Bergman, University of California, Berkeley
T. Don Tilley, University of California, Berkeley

Document Type

Article

Publication Date

4-16-2015

Abstract

Bis(perfluorocatecholato)silane Si(cat^F)₂ was prepared, and stoichiometric binding to Lewis bases was demonstrated with fluoride, triethylphosphine oxide, and N,N′-diisopropylbenzamide. The potent Lewis acidity of Si(cat^F)₂ was suggested from catalytic hydrosilylation and silylcyanation reactions with aldehydes. Mechanistic studies of hydrosilylation using an optically active silane substrate, R-(+)-methyl-(1-naphthyl)phenylsilane, proceeded with predominant stereochemical retention at silicon, consistent with a carbonyl activation pathway. The enantiospecificity was dependent on solvent and salt effects, with increasing solvent polarity or addition of NBu₄BAr^F₄ leading to a diminished enantiomeric ratio. The medium effects are consistent with an ionic mechanism, wherein hydride transfer occurs prior to silicon–oxygen bond formation.

Comments

This is a pre-copy-editing, author-produced PDF of an article accepted for publication in Journal of the American Chemical Society, volume 137, in 2015 following peer review. The definitive publisher-authenticated version is available online at https://doi.org/10.1021/jacs.5b02807.

Recommended Citation

Liberman-Martin, A. L.; Bergman, R. G.; Tilley, T. D. Lewis Acidity of Bis(perfluorocatecholato)silane: Aldehyde Hydrosilylation Catalyzed by a Neutral Silicon Compound. J. Am. Chem. Soc. 2015, 137, 5328–5331. https://doi.org/10.1021/jacs.5b02807

Copyright

American Chemical Society