[1 + 2] Cycloaddition of a Cyclic (Alkyl)(amino)silylene and a Disilyne Providing a 3‑Aminocyclotrisilene

Despite the notable progress in the chemistry of cycloaddition reactions of silylenes toward unsaturated bonds, such reactions toward a SiSi triple bond remain unknown. Herein, we report [1 + 2] cycloaddition of a cyclic (alkyl)­(amino)­silylene (1) and a dialkyldisilyne (2) to form a 3-aminocyclotrisilene (3). Cyclotrisilene 3 adopts a slightly cis-bent geometry with a relatively long SiSi double bond in the solid state, suggesting a π­(SiSi)−σ*­(Si–N) interaction. Thermolysis of 3 regenerated silylene 1, which was trapped as Et3SiH and toluene adducts at high temperatures.