Unusual Reactivity of Sodium Tetramesityltetraphosphanediide towards Cyclohexyl Isocyanide

The reaction of [Na2(thf)4(P4Mes4)] (Mes=2,4,6-Me3C6H2) with cyclohexyl isocyanide (2:5) resulted in the formation of the heterocyclic N-(tetramesityltetraphosphacyclopentylidene)cyclohexylamine [cyclo-{P4Mes4C(NCy)}] (2) (30–35 %), the unusual 1,3,5-triphospha-1,4-pentadiene (3) (40–45 %), and small amounts of the dimeric iminomethylidenephosphane cyclo-{PMesC(NCy)}2(4). With catalytic amounts of AgBF4, 2 was the major product. The reaction of 2 with [CuBr(SMe2)] (1:1) produced bromido-bridged dimeric CuIcomplex 5. Molecular structures of compounds 3, 4, and 5 were obtained.