Some recent applications of Fischer carbenemetal complexes in organic synthesis

Fischer-Type Carbene Complexes of Tris(1,4-phenylene)amines and Tri(2-furyl)phosphine

“…This is a direct consequence of the well-known strong electronwithdrawing ability of the (CO) 5 MC group, which behaves in a manner similar to that of a Lewis acid complexed carbonyl function. [33][34][35]42 Similar SOPT energies have been computed for the analogous complex 1a (ΔE (2) = −31.2 kcal/mol vs −14.8 and −15.1 kcal/mol).…”

Synthesis, Structure, and Electrochemistry of Fischer Alkoxy- and Aminocarbene Complexes of Tungsten: The Use of DFT To Predict and Understand Oxidation and Reduction Potentials

“…20,21,14 The classical "Fischer route" is still the most popular and makes use of the addition of lithium salts of organic substituents to the metal carbonyl reagent. This is followed by O-alkylation using hard alkylation agents, thus yielding alkoxycarbenes.…”

Electrochemical and Computational Study of Tungsten(0) Ferrocene Complexes: Observation of the Mono-Oxidized Tungsten(0) Ferrocenium Species and Intramolecular Electronic Interactions

“…27 Consistent with NHR (R = Bu, Pr) being a more powerful electron-donating group than OEt, the NHPr group shifted the wave I a peak cathodic potential, E pc , of the bis W=C species 4 compared to 2 with ΔE pc = E pc, OEt, 2 -E pc, NHBu, 4 = -1.773 -(-2.293) = 0.520 to more negative potentials. The next redox process observed for 1 -4 is the chemically and electrochemically one-electron reversible oxidation of ferrocene which is associated with wave Fc in Figure's 4, 5 and 6, and 5 ] where the ferrocenyl group was oxidized after oxidation of the Cr(0) center to Cr(I). 10,11 The second oxidation of Cr(I) to Cr(II) follows after the ferrocenyl oxidation, and also contrasts with the three-electron closely-overlapping W oxidation under the same experimental conditions.…”

“…4 Fischer carbene complexes are versatile organometallics with valuable applications in organic and organometallic synthesis as well as in the fields of bioorganometallics and materials chemistry. 5 Recently, computational studies especially enhanced the understanding of this group of organometallic compounds substantially. 6 The first examples of ferrocenyl carbene complexes of the group 6 transition metals, [(CO) 5 Cr=C(OR)Fc] (R = Me, Et), were synthesized to study the electronic effects of the ferrocenyl substituent on the carbene ligand as part of an investigation into the electron withdrawing nature of metal carbonyl carbene groups.…”

“…5 Recently, computational studies especially enhanced the understanding of this group of organometallic compounds substantially. 6 The first examples of ferrocenyl carbene complexes of the group 6 transition metals, [(CO) 5 Cr=C(OR)Fc] (R = Me, Et), were synthesized to study the electronic effects of the ferrocenyl substituent on the carbene ligand as part of an investigation into the electron withdrawing nature of metal carbonyl carbene groups. 7 Early hints of the increased stability and chemodirecting steric effect of ferrocenyl carbene complexes were reported by Dötz et al 8 Reaction of these ferrocenyl carbene complexes with tolane gave unexpected furanoid products over the customary Dötz benzannulation that yields chromium-coordinated hydroquinones.…”