Enantioselective synthesis of silicon-stereogenic sulfur-containing silanes via organocatalytic remote C-H sulfenylation of arenes.

In this study, we report a remote C-H sulfenylation of 5,10-dihydrophenazasilines enabled by a cooperative catalytic system comprising a chiral Lewis base and an achiral Brønsted acid for the first time. The synergistic use of a chiral phosphoric triamide sulfide catalyst featuring a bis((S)-1-phenylpropyl)amine structural motif and an achiral sulfonic acid co-catalyst with precisely tuned acidity is essential for achieving efficient remote stereocontrol. This methodology provides efficient access to chiral silicon-stereogenic sulfur-containing organosilanes. A broad substrate scope is demonstrated, affording the desired products in moderate to excellent yields (up to 94%) and with moderate to excellent enantioselectivities (up to >99% ee). Mechanistic investigations through control experiments suggest that the reaction proceeds via sequential desymmetrization and kinetic resolution processes. Density functional theory (DFT) calculations further demonstrate that multiple weak C-H⋯π interactions, together with the torsional distortion of the substrate, are crucial for the observed enantioselectivity.