Synthesis, Structure and Reactivity of a Cyapho(dicyano)methanide Salt

We describe the synthesis of a cyapho(dicyano)methanide salt, [K(18-crown-6)][C(CN)2(CP)], from reaction [Na(18-crown-6)][PH2] (18-crown-6=1,4,7,10,13,16-hexaoxacyclooctadecane) with 1,1-diethoxy-2,2-dicyanoethylene (EtO)2C=C(CN)2. The proceeds through Michael addition-elimination pathway to afford [Na(18-crown-6)][HP{C(OEt)=C(CN)2}]. Addition strong, non-nucleophilic base (KHMDS) this intermediate results in formation [K(18-crown-6)][C(CN)2(CP)]. Subsequent reactivity studies reveal that ion is susceptible protonation strong acids parent acid HC(CN)2(CP). cyaphide moiety [C(CN)2(CP)]− was explored coordination metal centers and cycloaddition reactions azides.