Neutral Hexacoordinate Phosphorus: Substituted Carbodiimide Phosphoranes and Other Chelated Substituted 2-Pyridine Derivatives

Abstract

Abstract A series of neutral hexacoordinate λ6 phosphorus compounds of the general formula X4-n(CF3)nPN(R)C(C1)N(R) (n = 0, 1, 2, 3; R = cyclohexyl, isopropyl) has been prepared. The parent compounds are obtained by “insertion” of carbodiimide into the P-C1 bond of λ5-chlorophosphorane. Substituted pyridines also react readily with λ5 chloro and fluoro phosphoranes to form 2-methylamino, thio and oxopyridine chelates of the form X4P(Epy) (E = 0, NMe and S; X = F, Cl) in which the phosphorus achieves six coordination through acceptance of the pyridine nitrogen. Selected reactions and the fluxional behavior of the λ6 systems are discussed.