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

Reactions of 2 H ‐azaphosphirene complex 1 with electron‐rich nitrile derivatives 2a – e in the presence of substoichiometric amounts of ferrocenium hexafluorophosphate yielded regioselectively 2 H ‐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 C 6 F 5 CN ( 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)