Template-controlled formation of an [11]ane-P2CNHC macrocyclic ligand at an iron(II) template

Abstract

Complex [Fe(η5-C5H5) (η6-PhMe)]PF6 reacts with l,2-bis[bis-(2-fluorophenyl)phosphanyl] benzene (2) in acetonitrile under irradiation for 6 h to give complex [Fe(η5-C5H5)(2)-(CH3CN)]PF 6 ([3]JPF6). Reaction of [3]PF6 with 1 equiv. of 2-azidoethyl isocyanide (4) yields complex [Fe(η5-C 5H5)(2)-(4)]X ([5]X) (X = Br, PF6). Staudinger reaction with PPh3 at the azido function followed by hydrolysis of the iminophos phorane with HBr yields compound [6]X (X = Br-, PF 6-) with an NH, NH-stabilized NHC ligand. The facially coordinated NH, NH-stabilized NHC and the fluorinated diphosphane ligands were linked by N,N′-deprotonation of the NHC and nucleophilic attack of the nitrogen atoms at two C-F bonds, which gave - after anion exchange with NH 4PF6 - complex [1]PF6 bearing the macrocyclic [11] ane-P2CNHC ligand. © 2010 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.