Regio- and Diasteroselective C-Silylation of Enolate Enabled by a β-Boronyl Group

Silyl enol ethers are often obtained when the lithium enolates are trapped with chlorosilanes. Herein, we report a general method for the regio- and diasteroselective C-silylation of enolate enabled by the β-boronyl group. The formation of five-membered chelation intermediate is key to the C-selective silylation and anti-selectivity. The operationally simple protocol provides a general and predictable access to the α-silylated esters. The synthetic versatility of the boron–silicon bifunctional products was demonstrated by down-stream transformations.