Chemistry of (Pentabenzylcyclopentadienyl)iron Compounds Including 17-Electron Dithiocarbamate Complexes

Abstract

C 5 (CH 2 Ph) 5 H, C 5 Bz 5 H, 1, the precursor of the useful C 5 Bz 5 ligand that was introduced by Rausch, has been synthesized in 85% yield, a slight improvement over the 62% yield very recently reported by Rausch. [Fe(C 5 Bz 5 )(CO) 2 ], 2, also reported by Rausch, could be obtained in 72% yield as the only product of the reaction between 1 and [Fe(CO) 5 ] at 90 °C for 4 days. Reaction of 1 with Br 2 gives [Fe(C 5 Bz 5 )(CO) 2 Br], 3, in 84% yield. Photolysis of 3 in THF using visible light in the presence of Na + S 2 CNMe 2 -(Na + dtc -) gives a 73% yield of [Fe(C 5 Bz 5 )(CO)(η 2 -dtc)], 4, whose oxidation by [FeCp 2 ] + PF 6 -gives the 17electron complex [Fe III (C 5 Bz 5 )(η 2 -dtc)(NCMe)] + PF 6 -, 5, the precursor of [Fe IV Cp*(η 2 -dtc) 2 ] + -PF 6 -, 7. Cyclic voltammetry studies of the C 5 Bz 5 -iron complexes show that the electronic properties of C 5 Bz 5 are intermediate between those of C 5 H 5 (Cp) and C 5 Me 5 (Cp*) and that C 5 Bz 5 destabilizes paramagnetic iron complexes as opposed to the stabilizing property of Cp*.

Iron(II) Complexes Bearing Chelating Cyclopentadienyl-N-Heterocyclic Carbene Ligands as Catalysts for Hydrosilylation and Hydrogen Transfer Reactions

“…The shift to lower frequency in compound 4 is a consequence of the stronger donor capacity of the tetramethylcyclopentadienyl ring compared to the unsubstituted-Cp and tetrabenzyl-cyclopentadienyl ligand. The less electron-donating capacity of the benzyl-substituted cyclopentadienyl ligand compared to the Cp* ligand has been already observed in complexes containing the [Fe(C 5 Bz 5 )] fragment …”

Synthesis of Ruthenium Carbonyl Complexes with Phosphine or Substituted Cp Ligands, and Their Activity in the Catalytic Deoxygenation of 1,2-Propanediol

“…27 Astruc and co-workers reported electrochemical data for iron compounds which showed that C 5 Bz 5 was not as electron-donating as Cp*. 28 Synthesis of [(1,2,3-Trimethylindenyl)Ru(CO)(μ-CO)] 2 . Metal complexes with indenyl ligands can show significantly different reactivity compared to Cp ligands.…”

“…Molybdenum complexes with C 5 Bz 5 ligands have been used in the catalytic epoxidation of olefins and in the catalytic ionic hydrogenation of ketones . Astruc and co-workers reported electrochemical data for iron compounds which showed that C 5 Bz 5 was not as electron-donating as Cp* …”

“…All manipulations were carried out under an atmosphere of argon using Schlenk or vacuum-line techniques, or in a Vacuum Atmospheres drybox. Quantitative analysis of the intermediates and products was carried out by gas chromatography, using an internal standard for integration, following protocols previously described in detail. , Preparations of HCp i Pr 4 , HC 5 Bz 5 , 1,2,3-trimethylindene, Tp*Ru(COD)H, Tp*Ru(CO) 2 H, Cp*Ru(CO) 2 H, and {[CpRu(CO) 2 ] 2 (μ-H)} + OTf −9 were carried out according to the literature procedures. CpRu(CO)(PCy 3 )H was prepared by a minor modification of the route described by Heinekey .…”

Reactivity of a Sterical Flexible Pentabenzylcyclopentadienyl Samarocene

“…In 1986, Rausch et al reported the first metal complexes featuring a Cp Bz5 ligand [2]. Subsequently, this ligand found use in the synthesis of a whole series of different complexes [3][4][5]. In 2015, Trifonov et al synthesized the first divalent lanthanide complexes ligated by two Cp Bz5 ligands, obtaining the corresponding divalent complexes [Cp Bz5 2 Ln] with Ln = Eu(II), Yb(II) and Sm(II).…”