Asymmetric catalysis is one of the most attractive and efficient ways of synthesizing chiral enantioenriched compounds from achiral precursors. Compared with the well-investigated enantioselective preparation of carbon-stereogenic compounds, the corresponding preparation of silicon-stereogenic compounds is much less established. In particular, the available methods typically rely on the use of stoichiometric amounts of chiral reagents, and little progress has been made on catalytic enantioselective synthesis using prochiral organosilanes until recently. This Focus Review highlights recent advances in the catalytic enantioselective preparation of silicon-stereogenic organosilanes under transition-metal catalysis through desymmetrization of prochiral organosilanes including diorganodihydrosilanes and tetraorganosilanes.

A rhodium-catalyzed asymmetric synthesis of silicon-stereogenic dibenzosiloles has been developed through a [2+2+2] cycloaddition of silicon-containing prochiral triynes with internal alkynes. High yields and enantioselectivities have been achieved by employing an axially chiral monophosphine ligand, and the present catalysis is also applicable to the asymmetric synthesis of a germanium-stereogenic dibenzogermole. Preliminary studies on the optical properties of these compounds are also described.

A rhodium-catalyzed asymmetric synthesis of silicon-stereogenic dibenzosiloles has been developed through a [2+2+2] cycloaddition of silicon-containing prochiral triynes with internal alkynes. High yields and enantioselectivities have been achieved by employing an axially chiral monophosphine ligand, and the present catalysis is also applicable to the asymmetric synthesis of a germanium-stereogenic dibenzogermole. Preliminary studies on the optical properties of these compounds are also described.

A potassium-bis(trimethylsilyl)amide-mediated cyclopropanation of allyl phosphates with silylboronates has been developed. Unlike the reported copper-catalyzed allylic substitution reactions, the nucleophile selectively attacks at the β-position of the allylic substrates under the present reaction conditions. The mechanism of this process has also been investigated, thus indicating the involvement of a silylpotassium species as the active nucleophilic component.

A potassium-bis(trimethylsilyl)amide-mediated cyclopropanation of allyl phosphates with silylboronates has been developed. Unlike the reported copper-catalyzed allylic substitution reactions, the nucleophile selectively attacks at the β-position of the allylic substrates under the present reaction conditions. The mechanism of this process has also been investigated, thus indicating the involvement of a silylpotassium species as the active nucleophilic component.