Nickel‐Catalyzed Enantioselective Reductive Cyclization of 1,3‐Dienes Toward α‐Chiral Six‐Membered Silacycles

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. Our strategy represents the first reductive cyclization involving both C–Si bond and C–C bond formation and 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.