Nickel-Catalyzed Sila-Cycloaddition of Dichlorodisilanes: Selective Si─Cl Activation for Cyclic Disilanes and...

Disilanyl architectures holds significant value across diverse fields, particularly in the development of advanced materials. However, their limited accessibility has hindered broader exploration. Herein, we report a catalytic strategy for the synthesis of structurally diverse cyclic disilanes through a [4 + 2] sila-cycloaddition between readily available dichlorodisilanes and 1,3-dienes. This transformation proceeds under mild, reductive nickel catalysis via an unusual Si─Cl bond activation pathway and accommodates a broad range of dienes, including bulk feedstocks, cyclic, multi-substituted, aliphatic, aromatic dienes, and trienes. An asymmetric variant further enables the efficient construction of chiral disilane frameworks with high enantioselectivity. The resulting disilacarbocycle adopts boat-like conformations, as revealed by X-ray analysis, due to the elongated Si─Si and Si─C bonds. Mechanistic studies suggest that a triplet Ni⁰ species engages in an S_N2-type oxidative addition to the Si─Cl bond, favoring this pathway over a concerted Si─Si activation. The resulting Si─Ni(I) intermediates are energetically preferred over Si─Ni(II) analogs in the subsequent diene insertion step.