Tetraferrocenyl[5]cumulene, (Fc)2C=C=C=C=C=C(Fc)2: Synthesis, Electrochemistry, and Reactivity, Including Nickel(0)-Promoted [3]Ferrocenophane Formation and [2+2] Cycloaddition w

详细信息    查看全文

• 作者：Benno Bildstein ; Manuela Schweiger ; Herbert Angleitner ; Holger Kopacka ; Klaus Wurst ; Karl-Hans Ongania ; Marco Fontani ; and Piero Zanello
• 刊名：Organometallics
• 出版年：1999
• 出版时间：October 11, 1999
• 年：1999
• 卷：18
• 期：21
• 页码：4286 - 4295
• 全文大小：196K
• 年卷期：v.18,no.21(October 11, 1999)
• ISSN：1520-6041

文摘

Tetraferrocenyl[5]cumulene (Fc)₂C=C=C=C=C=C(Fc)₂ (Fc = ferrocenyl) is synthesizedfrom 1,1-diferrocenyl-1-methoxypropyne by formal dimerization of diferrocenylethenylidenecarbene generated in situ by deprotonation and elimination of methoxide. The cumulene isan air-stable compound of blue color with an electron-rich cumulene moiety, as indicated byvarious spectroscopic methods. In contrast to other (shorter) ferrocenyl cumulenes whichshow no reactivity due to steric hindrance, (Fc)₂C=C=C=C=C=C(Fc)₂ is a quite reactivecompound, as exemplified by (i) transition metal complex formation with Rh(I), (ii)[3]ferrocenophane generation by Ni(0)-promoted intramolecular electrophilic aromaticsubstitution, and (iii) [2+2] cycloaddition with olefins and alkynes, and (iv) [2+2] cycloaddition with C₆₀ and C₇₀, yielding the first cumulene derivatives of fullerenes. MS, UV-vis,IR, Raman, NMR, cyclic voltammetry, controlled potential coulometry, Mössbauer spectroscopy, and X-ray single-crystal structure analysis have been performed to characterize thenew compounds.