3-Silylated Cyclohexa-1,4-dienes as Surrogates for Gaseous and Harmful Hydrosilanes in Lewis-Acid Catalysis

• Applicant: Professor Dr. Martin Oestreich
• Subject Area: Organic Molecular Chemistry - Synthesis and Characterisation
• Term: from 2014 to 2018
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 255836950

The ability of the commercially available Lewis acid B(C6F5)3 to activate Si-H bonds under mild reaction conditions has led to a number of synthetically useful applications since its discovery by Piers and co-workers. Our laboratory recently disclosed for the first time that the same strong Lewis acid is able to activate a bisallylic C-H bond in 3-silylated cyclohexa-1,4-dienes, thereby catalyzing the release of hydrosilanes with concomitant formation of benzene. This procedure is particularly attractive for the generation of otherwise gaseous, highly flammable and/or harmful hydrosilanes. The readily available 3-silylated cyclohexa-1,4-dienes are easy-to-handle liquids and represent hydrosilane surrogates. The combination of the B(C6F5)3-catalyzed silane release and subsequent Si-H bond activation then paved the way to the development of an unprecedented ionic transfer hydrosilylation of alkenes. We plan to elaborate our new methodology further and expand its application in Lewis-acid catalysis based on these fundamental findings. The major goal will be the identification of suitable transfer reagent/boron Lewis acid combinations for the release and transfer of functionalized silanes.

• DFG Programme: Research Grants