The novel cationic diiron m-allenyl complexes [Fe(2)Cp(2)(CO)(2)(mu-CO){mu-eta(1):eta(2)(alpha,beta)-C(alpha)(H)=C(bet a)=C(gamma)(R)(2)}](+) (R = Me, 4a; R = Ph, 4b) have been obtained in good yields by a two-step reaction starting from [Fe(2)Cp(2)(CO)(4)]. The solid state structures of [4a][CF(3)SO(3)] and of the diruthenium analogues [Ru(2)Cp(2)(CO)(2)(mu-CO){mu-eta(1):eta(2)(alpha,beta)-C(alpha)(H)=C(bet a)=C(gamma)(R)(2)}][BPh(4)] (R= Me, [2a][BPh(4)]; R = Ph, [2c][BPh(4)]) have been ascertained by X-ray diffraction studies. The reactions of 2c and 4a with Bronsted bases result in formation of the mu-allenylidene compound [Ru(2)Cp(2)(CO)(2)(mu-CO){mu-eta(1):eta(1)-C(alpha)=C(beta)=C(gamma)(Ph) (2)}] (5) and of the dimetallacyclopentenone [Fe(2)Cp(2)(CO)(mu-CO){mu-eta(1):eta(3)-C(alpha)(H)=C(beta)(C(gamma)(Me) CH(2))C(=O)}] (6), respectively. The nitrile adducts [Ru(2)Cp(2)(CO)(NCMe)(mu-CO){mu-eta(1):eta(2)-C(alpha)(H)=C(beta)=C(gamm a)(R)(2)}](+) (R = Me, 7a; R = Ph, 7b), prepared by treatment of 2a, c with MeCN/Me(3)NO, react with N(2)CHCO(2)Et/ NEt(3) at room temperature, affording the butenolide-substituted carbene complexes [Ru(2)Cp(2)(CO)(mu-CO){mu-eta(1):eta(3)-C(alpha)(H)C(beta)C(gamma)(R)(2) OC(=O)C(H)] (R = Me, 10a; R = Ph, 10b). The intermediate cationic compound [Ru(2)Cp(2)(CO)(mu-CO){mu-eta(1):eta(3)-C(alpha)(H)C(beta)C(gamma)(Me)(2 )OC(OEt)C(H)](+) (9) has been detected in the course of the reaction leading to 10a. The addition of N(2)CHCO(2)Et/NHEt(2) to 7a gives the 2-furaniminium-carbene [Ru(2)Cp(2)(CO)(mu-CO){mu-eta(1):eta(3)-C(alpha)(H)C(beta)C(gamma)(Me)(2 )OC(OEt)C(H)](+) (11). The X-ray structures of 10a, 10b and [11][BF(4)] have been determined. The reactions of 4a, b with MeCN/Me(3)NO result in prevalent decomposition to mononuclear iron species.

Cationic Diiron and Diruthenium µ-Allenyl Complexes: Synthesis, X-Ray Structures and Cyclization Reactions with Ethyldiazoacetate/Amine Affording Unprecedented Butenolide- and Furaniminium-Substituted Bridging Carbene Ligands

MARCHETTI, FABIO;PAMPALONI, GUIDO;
2010-01-01

Abstract

The novel cationic diiron m-allenyl complexes [Fe(2)Cp(2)(CO)(2)(mu-CO){mu-eta(1):eta(2)(alpha,beta)-C(alpha)(H)=C(bet a)=C(gamma)(R)(2)}](+) (R = Me, 4a; R = Ph, 4b) have been obtained in good yields by a two-step reaction starting from [Fe(2)Cp(2)(CO)(4)]. The solid state structures of [4a][CF(3)SO(3)] and of the diruthenium analogues [Ru(2)Cp(2)(CO)(2)(mu-CO){mu-eta(1):eta(2)(alpha,beta)-C(alpha)(H)=C(bet a)=C(gamma)(R)(2)}][BPh(4)] (R= Me, [2a][BPh(4)]; R = Ph, [2c][BPh(4)]) have been ascertained by X-ray diffraction studies. The reactions of 2c and 4a with Bronsted bases result in formation of the mu-allenylidene compound [Ru(2)Cp(2)(CO)(2)(mu-CO){mu-eta(1):eta(1)-C(alpha)=C(beta)=C(gamma)(Ph) (2)}] (5) and of the dimetallacyclopentenone [Fe(2)Cp(2)(CO)(mu-CO){mu-eta(1):eta(3)-C(alpha)(H)=C(beta)(C(gamma)(Me) CH(2))C(=O)}] (6), respectively. The nitrile adducts [Ru(2)Cp(2)(CO)(NCMe)(mu-CO){mu-eta(1):eta(2)-C(alpha)(H)=C(beta)=C(gamm a)(R)(2)}](+) (R = Me, 7a; R = Ph, 7b), prepared by treatment of 2a, c with MeCN/Me(3)NO, react with N(2)CHCO(2)Et/ NEt(3) at room temperature, affording the butenolide-substituted carbene complexes [Ru(2)Cp(2)(CO)(mu-CO){mu-eta(1):eta(3)-C(alpha)(H)C(beta)C(gamma)(R)(2) OC(=O)C(H)] (R = Me, 10a; R = Ph, 10b). The intermediate cationic compound [Ru(2)Cp(2)(CO)(mu-CO){mu-eta(1):eta(3)-C(alpha)(H)C(beta)C(gamma)(Me)(2 )OC(OEt)C(H)](+) (9) has been detected in the course of the reaction leading to 10a. The addition of N(2)CHCO(2)Et/NHEt(2) to 7a gives the 2-furaniminium-carbene [Ru(2)Cp(2)(CO)(mu-CO){mu-eta(1):eta(3)-C(alpha)(H)C(beta)C(gamma)(Me)(2 )OC(OEt)C(H)](+) (11). The X-ray structures of 10a, 10b and [11][BF(4)] have been determined. The reactions of 4a, b with MeCN/Me(3)NO result in prevalent decomposition to mononuclear iron species.
2010
Boni, A; Marchetti, Fabio; Pampaloni, Guido; Zacchini, S.
File in questo prodotto:
File Dimensione Formato  
55 Dalton Trans.pdf

solo utenti autorizzati

Tipologia: Documento in Post-print
Licenza: NON PUBBLICO - Accesso privato/ristretto
Dimensione 409.1 kB
Formato Adobe PDF
409.1 kB Adobe PDF   Visualizza/Apri   Richiedi una copia

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11568/205980
Citazioni
  • ???jsp.display-item.citation.pmc??? 2
  • Scopus 14
  • ???jsp.display-item.citation.isi??? 14
social impact