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.