New metallapyrrole complexes from [M2(μ-CNMe2)(μ-CO)(CO)2(Cp)2]SO3CF3 (M=Fe, Ru) and acetonitrile anions; structure of [(Cp)(CO)(CN)]

Journal of Organometallic Chemistry

Zacchini

et al. 2005

Self Cite

The diiron complexes [Fe(Cp)(CO){μ-η2:η2-C[N(Me)(R)]NC(C6H3R′)CCH(Tol)}Fe(Cp)(CO)] (R = Xyl, R′ = H, 3a; R = Xyl, R′ = Br, 3b; R = Xyl, R′ = OMe, 3c; R = Xyl, R′ = CO2Me, 3d; R = Xyl, R′ = CF3, 3e; R = Me, R′ = H, 3f; R = Me, R′ = CF3, 3g) are obtained in good yields from the reaction of [Fe2{μ-CN(Me)(R)}(μ-CO)(CO)(p-NCC6H4R′)(Cp)2]+ (R = Xyl, R′ = H, 2a; R = Xyl, R′ = Br, 2b; R = Xyl, R′ = OMe, 2c; R = Xyl, R′ = CO2Me, 2d; R = Xyl, R′ = CF3, 2e; R = Me, R′ = H, 2f; R = Me, R′ = CF3, 2g) with TolCCLi. The formation of 3 involves addition of the acetylide at the coordinated nitrile and C–N coupling with the bridging aminocarbyne together with orthometallation of the p-substituted aromatic ring and breaking of the Fe–Fe bond. Complexes3a–e which contain the N(Me)(Xyl) group exist in solution as mixtures of the E-trans and Z-trans isomers, whereas the compounds 3f,g, which posses an exocyclic NMe2 group, exist only in the Z-cis form. The crystal structures of Z-trans-3b, E-trans-3c, Z-trans-3e and Z-cis-3g have been determined by X-ray diffraction experiments

Section: R'supporting

confidence: 64%

“…the configuration of the exocyclic C(15)@C (16) bond, which adopts a Z configuration in 3b, 3e and 3g whereas it is E in 3c. Therefore the compounds shown in Figs.…”

Section: R'mentioning

confidence: 99%

Section: R'mentioning

confidence: 99%

See 1 more Smart Citation

Nitrile ligands activation in dinuclear aminocarbyne complexes

Busetto

Journal of Organometallic Chemistry

Zacchini

et al. 2005

Self Cite

“…A limited number of vinyliminium complexes 29 (R′′ = H) is involved in the deprotonation routes shown in Scheme . The remaining compounds, bearing different combinations of R and R′, react with sodium hydride (and also other bases such as amines) to give the mononuclear derivatives 46 that maintain the C 1 –C 2 –C 3 chain (Scheme ),, through the unusual fragmentation of the diiron skeleton . The same outcome is observed when complexes 29 (R′′ ≠ H) are treated with NaH .…”

Section: Reactivity Of Vinyliminium Complexesmentioning

confidence: 99%

Constructing Organometallic Architectures from Aminoalkylidyne Diiron Complexes

2018

Eur J Inorg Chem

The chemistry of diiron complexes has seen a recent renaissance, due to the prominent role played by the element iron in the development of sustainable synthetic processes and the cooperative effects provided by two metal centers working in concert, that is a concept amazingly exploited by Nature. Aminoalkylidyne derivatives of [Fe 2 Cp 2 (CO) 4 ] are a convenient scaffold to grow organic fragments; in particular, the facile re-[a] received his PhD degree in Chemistry from the University of Bologna in 2003, then he moved to the University of Pisa in 2006, where he is currently Professor of Inorganic Chemistry. He has co-authored over 150 papers in international journals, dealing with several aspects of the coordination chemistry of transition metal compounds. He was awarded the Nasini Prize by the Italian Chemical Society in 2014, for his contribution to the chemistry of group 5 and 6 metal compounds and to the exploration of unconventional modes of metal mediated C-C bond formation. 3990 Scheme 7. Coupling of isocyanide ligands promoted by acetylide addition to aminoalkylidyne complexes. (a) R = Xyl, R′ = Ph; R = Xyl, R′ = 4-C 6 H 4 Me; R = Me, R′ = Ph. (b) γ-Al 2 O 3 , R′ = SiMe 3 . [51]Eur. 3991Scheme 8. Base-assisted coupling of aminoalkylidyne ligand (R = Me, Xyl or 4-C 6 H 4 OMe) with (a) alkenes (R′ = H, R′′ = CN, CO 2 Me, Ph; R′ = R′′ = CO 2 Et) [53] and (b) allenes (R′ = R′′ = Me; R′ = Me, CO 2 Et, R′′ = H). [54] Scheme 9. Synthesis of vinyliminium complexes via alkyne insertion into Fe-μ-carbyne bond. Inset: possible forms of isomerism. [61][62][63] Eur.

“…However, it has to be considered that diiron and diruthenium aminocarbyne complexes can react with LiR in a variety of ways. In fact, beside ligand substitution, other reaction paths are available: i) nucleophilic addition at CO or Cp ligands to give stable acyl and cyclopentadiene derivatives, respectively [14]; ii) reduction and fragmentation of the dinuclear frame [15]; iii) nucleophilic addition at the coordinated nitrile [7 -8]; iv) removal of acidic protons [16]. This latter possibility was observed previously upon treatment of 1a -c with LiR: the MeCN ligand is deprotonated and rearranges to a cyanomethyl group affording the complexes [Fe 2 {µ-CN(Me)(R)}(µ-CO)(CO) (CH 2 CN)(Cp) 2 ] [16a].…”

Section: Substitution Reactions In Diiron and Diruthenium Aminocarbynmentioning

confidence: 99%

Synthesis and Characterization of New Diiron and Diruthenium μ-Aminocarbyne Complexes Containing Terminal S-, P- and C-Ligands

Albano

Busetto

Zeitschrift Für Naturforschung B

et al. 2007

Self Cite

The diiron aminocarbyne complexes [Fe 2 {µ-CN(Me)(R)}(µ-CO)(CO)(NCMe)(Cp) 2 ][SO 3 CF 3 ] (R = Xyl, 1a; R = Me, 1b; R = CH 2 Ph, 1c; Xyl = 2,6-Me 2 C 6 H 3 ) undergo replacement of the coordinated nitrile by halides, diethyldithiocarbamate, and dicyanomethanide to give [Fe 2 {µ-CN(Me) (R)}(µ-CO)(CO)(X)(Cp) 2 ] complexes (R = Me, X = Br, 4a; R = Me, X = I, 4b; R = CH 2 Ph, X = Cl, 4c; R = CH 2 Ph, X = Br, 4d; R = CH 2 Ph, X = I, 4e; R = Xyl, X = SC(S)NEt 2 , 5a; R = Me, X = SC(S)NEt 2 , 5b; R = Xyl, X = CH(CN) 2 , 7), in good yields. The molecular structure of 5a shows an unusual η 1 coordination mode of the dithiocarbamate ligand.a series of phosphanes generates the cationic complexes [M 2 {µ-CN(Me)(R)}(µ-CO)(CO)(P)(Cp) 2 ][SO 3 CF 3 ] (M = Fe, R = Xyl, P = PPh 2 H, 6a; M = Fe, R = Xyl, P = PPh 3 , 6b; M = Fe, R = Xyl, P = PMe 3 , 6c; M = Fe, R = Me, P = PMe 2 Ph, 6d; M = Fe, R = Me, P = PPh 3 , 6e; M = Fe, R = Me, P = PMePh 2 , 6f; M = Ru, R = Xyl, P = PPh 2 H, 6g; M = Ru, R = Me, P = PPh 2 H, 6h), in high yields. The molecular structure of 6a has been elucidated by an X-ray diffraction study. The reactions of [Fe 2 {µ-CN(Me)(Xyl)}(µ-CO)(CO)(NCR )(Cp) 2 ][SO 3 CF 3 ] [R = Me, 1a; R = tBu, 3] with PhLi and PPh 2 Li yield [Fe 2 {µ-CN(Me)(Xyl)}(µ-CO)(CO)(Ph)(Cp) 2 ] (8) and [Fe 2 {µ-CN(Me)(Xyl)}(µ-CO)(CO)(PPh 2 )(Cp) 2 ] (9), respectively. The molecular structure of 8 has been ascertained by X-ray diffraction. Conversely, the reaction of 1a with MeLi generates the aminoalkylidene compound [Fe 2 {C(Me)N(Me)(Xyl)}(µ-CO) 2 (CO)(Cp) 2 ] (10). Finally, the acetone complex [Fe 2 {µ-CN(Me)(Xyl)}(µ-CO)(CO)(OCMe 2 )(Cp) 2 ][SO 3 CF 3 ] (12) reacts with lithium acetylides to give complexes [Fe 2 {µ-CN(Me)(Xyl)}(µ-CO)(CO)(C≡CR)(Cp) 2 ] (R = p-C 6 H 4 Me, 11a; R = Ph, 11b; R = SiMe 3 , 11c), in high yields. Filtration through alumina of a solution of 11a in CH 2 Cl 2 results in hydration of the acetylide group and C-Si bond cleavage, affording [Fe 2 {µ-CN(Me)(Xyl)}(µ-CO)(CO){C(O)Me}(Cp) 2 ] (12).