Enantioselective Synthesis of Silicon-Stereogenic Monohydrosilanes by Rhodium-Catalyzed Intramolecular Hydrosilylation

Enantiopure monohydrosilanes are versatile chiral reagents for alcohol resolution and mechanistic investigation. Herein, we have demonstrated the asymmetric synthesis of monohydrosilanes via an intramolecular hydrosilylation strategy. This protocol is suitable for the synthesis of five- and six-membered cyclic monohydrosilanes, including a class of chiral oxasilacycles, with excellent diastereo-, regio-, and enantioselectivities. Notably, the catalyst loading could be reduced to 0.1 mol % which makes this one of the most efficient methods to access chiral monohydrosilanes. Mechanistic studies and DFT calculations indicate this Rh-catalyzed intramolecular asymmetric hydrosilylation reaction might proceed via a Chalk-Harrod mechanism, and the enantio-determining step was predicted to be oxidative addition of Si-H bond.

Automated summary

This study demonstrated an asymmetric synthesis method for monohydrosilanes via intramolecular hydrosilylation strategy, with high diastereo-, regio-, and enantioselectivities, including chiral oxasilacycles. The catalyst loading could be reduced to 0.1 mol %, making it one of the most efficient methods for accessing chiral monohydrosilanes. Mechanistic studies suggest a Chalk-Harrod mechanism for the Rh-catalyzed intramolecular asymmetric hydrosilylation reaction.