Evidence for Ligand‐Centered Reactivity of a 17e Radical Cationic 2H‐Azaphosphirene Complex

Reactions of 2H‐azaphosphirene complex 1 with electron‐rich nitrile derivatives 2a–e in the presence of substoichiometric amounts of ferrocenium hexafluorophosphate yielded regioselectively 2H‐1,4,2‐diazaphosphole complexes 3a–e under mild conditions. The dependence of the reaction on the amount of ferrocenium hexafluorophosphate is discussed. In the reactions of 1 with electron‐poor nitrile derivatives HCN (2f), EtOC(O)CN (2g), and C6F5CN (2h), byproducts possessing a P–F bond are formed, which indicates that the hexafluorophosphate anion is involved in the reaction course. Apart from NMR spectroscopic (3a–f) and X‐ray data (3b, 3d–e), a detailed DFT study is included that provides first insight into the reaction pathway.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)