Flash Communication: Cyanophosphide Transfer Reactions

Cyanophosphides of
the general form [RPCN]− can
be viewed as cyanide adducts of phosphinidenes and are phosphorus
species in the (+1)-oxidation state. We have recently reported on
the stable cyanophosphide [DippTerPCN]K (DippTer = 2,6-Dipp2C6H3, Dipp = 2,6-iPrC6H3) and now investigate its reactions
with ECln (E = Ge, n =
2; E = P, As, n = 3) in either salt metathesis or
base-assisted dehydrohalogenation reactions. In the case of GeCl2, salt metathesis with [DippTerPCN]K afforded the
dimer of a chlorogermylene [DippTerP(CN)GeCl]2. When only 0.5 equiv of GeCl2 was used, the diphosphanylgermylene
[DippTerP(CN)]2Ge was generated in solution.
With ECl3 (E = P, As), facile cyanophosphide transfer was
achieved from DippTerP(H)CN in NEt3-assisted
dehydrohalogenation, giving diphosphanes or arsaphosphanes of the
type DippTerP(CN)ECl2 (E = P, As), respectively.