Arene transition metal complexes

The first reported arene-transition metal trifluorophosphine complex [Cr(i/6-C6H6)(PF3)3] was obtained by UV irradiation of [Cr(i/6-C6H6)(C0)3] with PF3 (method A), whereas the corresponding thermal reaction afforded instead the mixed carbonyl trifluorophos- 

A rather unusual synthetic route to an 6-arene-metal-trifluorophosphine complex has been described in which displacement 

A variety of different preparative routes to this class of compounds have been utilized and the known complexes are listed in Table XI. 

There is only one report to date of the simple addition of PF3 to an /3-allyl-metal complex containing no other ligands (method A), namely, 

However, the complex slowly converts to [Cr(PF3)6]. A related route (method B) involves the displacement of one or more coordinated /3-allyl ligands, viz., 

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The use of transition-metal arene complexes to facilitate nucleophilic aromatic substitution features in a route to derivatives of thiosalicylic acid and hence to thioxanthone. The cyclopentadienyl iron complex of 2-chlorobenzoic acid is converted into the benzamide prior to displacement of the chloride by thiophenoxide. Photolytic decom-plexation followed by directed remote metallation of the diaryl sulfide yielded the heterocycle (Scheme 207) <2000SL975>. 

An interesting aspect is the application of these arene functionalised imidazolium salts as organometallic ionic liquids [139,142,143] whereby the imidazolium salt functions as the ionic liquid itself [139,143] or as the ionic liquid compatible part of the compound using the transition metal arene complex as a catalyst in biphasic applications [142],... 

Synthetic applications of the photochemistry of transition-metal arene complexes are rare, except for the (h -arene)M(CO)j (M = Cr, Mo, W) complexes where photo-substitution of ligands for CO occurs. These complexes also undergo arene exchange upon photolysis ... 

Semmelhack MF (1995) Transition metal arene complexes ring lithiation. In Abel EW, Stone EGA, Wilkinson G (eds) Comprehensive organometallic chemistry II. Pergamon... 

Among the known types of transition metal arene complexes, only q -benzene-Cr(CO)3 derivatives have received broad recognition by synthetic chemists. This is because such complexes are rather air-stable and easy to handle while the... 

Catalysis with transition-metal arene complexes has provided a new manifold of synthetic options. The broad features of accessible reaction pathways are well established, and organic chemists can feel comfortably about incorporating such methodology into their armory. We are sure that many new synthetically useful reactions using arene metal catalysts will be developed in the nearest future. 

Kiindig EP (2004) Synthesis of Transition Metal -Arene Complexes. 7 3-20 Kiindig EP, Pape A (2004) Dearomatization via Complexes. 7 71-94... 

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