Regioselective Addition of Tris(dialkylamino) Phosphines to [Fe2(CO)6(μ-PPh2){μ-η1:η2-(H)CCCH2}]: Novel P−C Coupling Reactions and Unusual Hydrocarbyl Rearrangements

C-C bond formation in diiron complexes

The growing effort to design new sustainable synthetic methodologies, based on readily available and environmentally friendly transition metals, has boosted research on iron complexes. This review article focuses on C-C-bond-forming reactions occurring at bridging ligands in diiron complexes, aimed at evidencing distinctive aspects and advantages associated with the presence of two adjacent iron centres. A number of diiron-mediated C-C-bond-forming reactions reported in the literature, including nucleophilic and electrophilic additions and insertion and cycloaddition reactions, have been accumulated over the years, which, together with more recent developments, indicate that diiron complexes might provide promising alternatives to precious metals in the challenging field of metal-promoted C-C bond formation.

From Diphosphane to Diphosphodiide Gold(III) Derivatives of 1,2-Diphosphinobenzene

Treatment of 1,2-diphosphinobenzene with [Au(C6F5)3(tht)] leads to the diphosphane derivative [{Au(C6F5)3}(1,2-PH2C6H4PH2)] (1), which further reacts with other pentafluorophenylgold(III) reagents in the presence of acetylacetonate as deprotonating agent to afford phosphane-phosphide complexes. The noncyclic PPN[{Au(C6F5)3}2(1,2-PHC6H4PH2)] (2; PPN = bis(triphenylphosphine)iminium) has been shown to be a useful starting material for the synthesis of higher nuclearity cyclic or noncyclic diphosphide or even diphosphodiide derivatives through similar reactions. The crystal structures of the trinuclear anionic NBu4[{Au(C6F5)3}(1,2-PHC6H4PH){Au(C6F5)2Cl}{mu-Au(C6F5)2}] (3) and the hexanuclear [{Au(C6F5)3}(1,2-PC6H4P){Au(C6F5)3}{mu-M(dppe)M}2] (M = Au (12), Ag (13)) have been established by X-ray diffraction methods, the last complexes having a bicyclic ring containing three intramolecular interactions between the M(I) centres.

Heteropolynuclear phosphide complexes: phosphorus as unique atom bridging coinage metal centres

In this paper we describe the synthesis and reactivity of the diphenylphosphine derivatives [Au(C6F5)(PPh2H)] and trans-[Au(C6F5)2(PPh2H)2]ClO4. Reactions of the latter or the neutral [Au(C6F5)3(PPh2H)] with the appropriate Group 11 metal reagents (M = Au, Ag, Cu) in the presence of acetylacetonate afford a series of novel Au(III)-M phosphido-bridged complexes, which have been scarcely represented to date. The crystal structure of the tetranuclear [(Au(C6F5)2(mu-PPh2)2Ag)2] and the dinuclear [Au(C6F5)3(mu-PPh2)M(PPh3)] (M = Au,Ag) complexes were established by X-ray diffraction methods. The synthesis and deprotonating activity of the anionic gold(III) complex PPN[Au(C6F5)3(acac)] (PNN = [N(PPh3)2]+) was studied.