title: Reactivity of iron complexes containing monodentate aminophosphine ligands - Formation of four-membered carboxamido-phospha-metallacycles.
abstract: Treatment of [FeCp(CO)2Cl] with 1 equiv of the amidophosphine ligands Li[R2PNR'] (R = Ph,iPr, R' =iPr,tBu, Cy) afforded complexes of the type [FeCp(CO)(κ2(C,P)-(C = O)-NiPr-PPh2)] (1a), [FeCp(CO)(κ2(C,P)-(C = O)-NtBu-PPh2)] (1b), and [FeCp(CO)(κ2(C,P)-(C = O)-NCy-PiPr2)] (1c) in 40-50% yields. Complex1awas also formed when [FeCp(CO)2(PPh2NHiPr)]+(2) was reacted with 1 equiv of KOtBu. These complexes feature a four-membered carboxamido-phospha-ferracycle as a result of an intramolecular nucleophilic attack of the amidophosphine ligand on coordinated CO. Upon treatment of1awith the electrophile [Me3O]BF4the aminocarbene complex [FeCp(CO)(κ2(C,P) = C(OMe)-NiPr-PPh2)]+(3) was obtained bearing an aza-phospha-carbene moiety. Upon treatment ofcis,trans,cis-[Fe(CO)2(Ph2PNHiPr)2(Br)2] (4a) andcis,trans,cis-[Fe(CO)2(Ph2PNHtBu)2(Br)2] (4b) with KOtBu the carboxamido-phospha-ferracyclestrans-[Fe(CO)2(κ2(C,P)-(C = O)-NiPr-PPh2)(Ph2PNHiPr)Br] (5a) andtrans-[Fe(CO)2(κ2(C,P)-(C = O)-NtBu-PPh2)(Ph2PNHtBu)Br] (5b) were formed in moderate yield. Finally, representative structures were determined by X-ray crystallography.
authors.affiliation: Institute of Applied Synthetic Chemistry, Vienna University of Technology, Getreidemarkt 9, A-1060 Vienna, Austria.
authors.forename: Ozgür
authors.initials: O
authors.lastname: Oztopcu
authors.forename: Berthold
authors.initials: B
authors.lastname: Stöger
authors.forename: Kurt
authors.initials: K
authors.lastname: Mereiter
authors.forename: Karl
authors.initials: K
authors.lastname: Kirchner
keywords: Aminophosphines; Carbon monoxide; Cyclopentadienyl; Ferracycles; Iron; Nucleophilic attack