Organic Amides as Suitable Precursors to Stabilize Stannylenes

This contribution demonstrates that deprotonated amides (amidates) can be used to stabilize stannylenes. Thus, the dimeric stannylene [Sn₂{μ-^tBuNC­(O)^tBu}₂Cl₂] (1) was obtained by treating Li­{^tBuNC­(O)^tBu} with 1 equiv of SnCl₂. Chloride exchange reactions of 1 with Li­{^tBuNC­(O)^tBu} and Li­(HMDS) (HMDS = N­(SiMe₃)₂) lowered aggregation, affording the monomeric tetra- and tricoordinated tin­(II) derivatives [Sn­{^tBuNC­(O)^tBu}₂] (2) and [Sn­{^tBuNC­(O)^tBu}­(HMDS)] (3), respectively. Alternatively, 3 can be prepared by direct deprotonation of the amide with Sn­(HMDS)₂. Compounds 1–3 are stannylenes that contain an unprecedented SnNCO four-membered ring.