Precise Activation of Ammonia and Carbon Dioxide by an Iminodisilene

The activation of NH3 and CO2 is still an ambitious target for multiply bonded sub‐valent silicon compounds. Now, the precise splitting of the N−H bond of ammonia by (Z)‐imino(silyl)disilene 1 to give trans‐1,2‐adduct 2 a at low temperatures (−78 °C) is presented. According to DFT calculations, the stereospecific hydroamination follows a similar mechanism as the recently reported anti‐addition of H2 to the Si=Si bond of 1. The aminosilane 2 b could also be obtained as the formal silylene addition product under thermodynamic reaction control. By applying low temperatures, the activation of CO2 with 1 selectively afforded the cis‐oxadisilacyclobutanone 7‐c as [2+2] cycloadduct. By performing the reaction directly at ambient temperatures, a mixture of three different‐sized silacycles (4–6) was observed. Their formation was investigated theoretically and their structures were revealed with separate experiments using 1 and the oxygenation agents N2O and O2. In pursuit of precision: The double donor–acceptor‐type Si=Si bond of a (Z)‐imino(silyl)disilene was exploited to selectively activate NH3, leading to the corresponding trans‐1,2‐adduct under kinetic and the monomeric aminosilane under thermodynamic reaction control. Furthermore, its reactivity toward Lewis acid B(C6F5)3 and the oxygen‐atom transfer agents N2O, O2, and CO2 was elucidated.