Nickel-Catalyzed Enantioselective Reductive Cyclization of 1,3-Dienes toward α-Chiral Six-Membered Silacyclic Skele-tons

Chiral organosilanes are increasingly important in synthetic, medicinal, and materials chemistry. However, the enantioselective synthesis of α-chiral six-membered silacycles remains unexplored. Here, we report two nickel-catalyzed enantioselective reductive [4+2] cyclizations of 1,3-dienes using readily available chloromethyl chlorosilane or 1,2-dichlorodisilane as dielectrophiles, proceeding via distinct mechanisms. This strategy enables efficient and highly enantioselective access to α-chiral silacyclohexenes and 1,2-disilacyclohexenes with broad functional group compatibility. Further derivatizations demonstrate the potential of this method for constructing valuable chiral silicon building blocks, underscoring its synthetic utility.