Alkyne–alkenyl coupling at a diruthenium complex

Bresciani, Giulio; Boni, Serena; Zacchini, Stefano; Pampaloni, Guido; Bortoluzzi, Marco; Marchetti, Fabio

doi:10.1039/d2dt02866b

Cited by 12 publications

(20 citation statements)

References 83 publications

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“…In fact, previous findings indicated that R may significantly affect the chemistry of this class of complexes [ 37 ]. Compounds [1a–d]CF 3 SO 3 were converted into the respective acetonitrile adducts [ 40 ] using the trimethylamine- N -oxide (TMNO) strategy, which is often reliable with cationic complexes based on the {M 2 Cp 2 (CO) 3 } core with M = Fe or Ru [ 41 , 42 , 43 , 44 ]. The resulting derivatives [1a NCMe –1d NCMe ]CF 3 SO 3 were used in all cases as freshly prepared reactants.…”

Section: Resultsmentioning

confidence: 99%

Diiron Aminocarbyne Complexes with NCE− Ligands (E = O, S, Se)

et al. 2023

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Diiron μ-aminocarbyne complexes [Fe2Cp2(NCMe)(CO)(μ-CO){μ-CN(Me)(R)}]CF3SO3 (R = Xyl, [1aNCMe]CF3SO3; R = Me, [1bNCMe]CF3SO3; R = Cy, [1cNCMe]CF3SO3; R = CH2Ph, [1dNCMe]CF3SO3), freshly prepared from tricarbonyl precursors [1a–d]CF3SO3, reacted with NaOCN (in acetone) and NBu4SCN (in dichloromethane) to give [Fe2Cp2(kN-NCO)(CO)(μ-CO){μ-CN(Me)(R)}] (R = Xyl, 2a; Me, 2b; Cy, 2c) and [Fe2Cp2(kN-NCS)(CO)(μ-CO){μ-CN(Me)(CH2Ph)}], 3 in 67–81% yields via substitution of the acetonitrile ligand. The reaction of [1aNCMe–1cNCMe]CF3SO3 with KSeCN in THF at reflux temperature led to the cyanide complexes [Fe2Cp2(CN)(CO)(μ-CO){μ-CNMe(R)}], 6a–c (45–67%). When the reaction of [1aNCMe]CF3SO3 with KSeCN was performed in acetone at room temperature, subsequent careful chromatography allowed the separation of moderate amounts of [Fe2Cp2(kSe-SeCN)(CO)(μ-CO){μ-CN(Me)(Xyl)}], 4a, and [Fe2Cp2(kN-NCSe)(CO)(μ-CO){μ-CN(Me)(Xyl)}], 5a. All products were fully characterized by elemental analysis, IR, and multinuclear NMR spectroscopy; moreover, the molecular structure of trans-6b was ascertained by single crystal X-ray diffraction. DFT calculations were carried out to shed light on the coordination mode and stability of the {NCSe-} fragment.

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Section: Resultsmentioning

confidence: 99%

Diiron Aminocarbyne Complexes with NCE− Ligands (E = O, S, Se)

et al. 2023

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“…Similarly, the C α and C γ resonances undergo a minor shift on going from 1 to 2a–c , and in 2a–c they occur at 63.5–65.9 and 196.6–197.6 ppm, respectively. The C γ carbon is almost equidistant between the two iron centers and possesses a bridging alkylidene nature, which is reflected in the low-field 13 C NMR signal. − Likewise in 1 , the N -methyl groups are nonequivalent in 2a–c , confirming the occurrence of intramolecular amine–CO interaction in solution [e.g., for 2a : δ( 1 H) = 2.27, 1.75 ppm; δ( 13 C) = 50.3, 41.5 ppm]. The phosphorus nucleus belonging to the isocyanide substituent in 2a is considerably affected by coordination, as witnessed by the shift of the related 31 P NMR resonance (from 14.0 ppm in uncoordinated isocyanide to 24.0 ppm in 2a ).…”

Section: Resultsmentioning

confidence: 99%

Construction of Two-Faced (Hetero)hydrocarbyl Diiron Complexes Mediated by the Interplay of Ligands

et al. 2023

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The functionalized allylidene complex [Fe 2 Cp 2 (CO)(μ-CO){μ-η 1 :η 3 -C γ (Fc)-C β HC α (CN)NMe 2 }], 1 [Cp = η 5 -C 5 H 5 ; Fc = CpFe(η 5 -C 5 H 4 )], reacted with isocyanides (CNR), in isopropanol solution at ca. 100 °C, to give the CO-substitution products [Fe 2 Cp 2 (CO)(μ-CNR){μ-η 1 :η], which were isolated in 61−84% yields. The bridging coordination of CNR in 2a−c is forced by a stabilizing electrostatic interaction between the nitrogen lone pair belonging to the {NMe 2 } group and the terminal CO ligand. Isocyanide methylation with methyl triflate proceeded with the inversion of stereochemistry at the C α carbon and led to [Fe 2 Cp 2 (CO){μ-CN(Me)R}{μ-η 1 :η), containing bridging allylidene and aminocarbyne ligands (68−74% yields). All products were fully characterized by IR and multinuclear NMR spectroscopy, and the structures of 2a and [3a]CF 3 SO 3 were elucidated by X-ray diffraction studies. Density functional theory (DFT) calculations were extensively carried out to shed light on structural, mechanistic, and thermodynamic features.

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“…The μ-aminocarbyne complexes [Fe 2 Cp 2 (CO) 2 (μ-CO){μ-CNMe (R)}]CF 3 SO 3 , 1a-d, readily available from multigram scale synthesis, were first converted into the mono-acetonitrile adducts [Fe 2 Cp 2 (CO)(NCMe)(μ-CO){μ-CNMe(R)}]CF 3 SO 3 (R = Me, 4-C 6 H 4 OMe, Cy, CH 2 Ph) 54 using the TMNO (trimethylamine-N-oxide) strategy. [55][56][57] The acetonitrile complexes, in dichloromethane solution, were then treated with a slight molar excess of a range of terminal alkynes containing cyclohexyl and/or para-methoxyphenyl substituents. Removal of the labile acetonitrile ligand by the alkyne is followed by regioselective alkyne insertion into the iron-bridging carbyne, to afford the vinyliminium products 2a-f (Scheme 1).…”

Section: Synthesis and Characterization Of Diiron Complexesmentioning

confidence: 99%