Palladium-catalyzed hydrosilylation of ynones to access silicon-stereogenic silylenones by stereospecific aromatic interaction-assisted Si-H activation

Hydrosilylation is one of the most important reactions in synthetic chemistry and ranks as a fundamental method to access organosilicon compounds in industrial and academic processes. However, the enantioselective construction of chiral-at-silicon compounds via catalytic asymmetric hydrosilylation remained limited and difficult. Here we report a highly enantioselective hydrosilylation of ynones, a type of carbonyl-activated alkynes, using a palladium catalyst with a chiral binaphthyl phosphoramidite ligand. The stereospecific hydrosilylation of ynones affords a series of silicon-stereogenic silylenones with up to 94% yield, >20:1 regioselectivity and 98:2 enantioselectivity. The density functional theory (DFT) calculations were conducted to elucidate the reaction mechanism and origin of high degree of stereoselectivity, in which the powerful potential of aromatic interaction in this reaction is highlighted by the multiple C-H-pi interaction and aromatic cavity-oriented enantioselectivity-determining step during desymmetric functionalization of Si-H bond.

Automated summary

The study presents a highly enantioselective hydrosilylation of ynones using a palladium catalyst with a chiral ligand, leading to the formation of a series of silicon-stereogenic silylenones with high yield and enantioselectivity. The reaction mechanism and origin of high degree of stereoselectivity were elucidated through density functional theory calculations, highlighting the importance of aromatic interactions in the reaction.