Multi-functionalized ferrocenes: –Synthesis and characterization –
摘要:
Ferrocenes with up to four formyl functionalities have been synthesized by selective one-or two-fold ortho-lithiation of 1,1'-di(1,3-dioxan-2-yl)ferrocene followed by the reaction with dimethylformamide. Subsequent deprotection afforded tri- and tetraformyl-ferrocene in good yields. Wittig reactions convert the aldehydes to tri-and tetravinyl-ferrocene. The structures of three formyl-ferrocenes in the solid-state have been determined by single crystal X-ray diffraction. In two of the structures the ferrocene moieties form 1D chains by parallel displaced p-interactions with Cp center dot center dot center dot Cp distances as short as 3.21 angstrom. Electrochemical measurements (CV) demonstrated an irreversible behavior of the electron-poor multi-formyl ferrocenes. Reducing the measurement temperature down to -40 degrees C and the usage of [(NBu4)-Bu-n][B(C6F5)(4)] prevents side reactions and hence reversible redox-processes could be obtained. It was found that the number of formyl functionalities correlates with the ferrocenyl's redox potential in a strictly linear fashion. (C) 2015 Elsevier B.V. All rights reserved.
The highly regiospecific synthesis and crystal structure determination of 1,1′-2,5′ substituted ring-locked ferrocenes
作者:Arthur Connell、Peter J. Holliman、Ian R. Butler、Louise Male、Simon J. Coles、Peter N. Horton、Michael B. Hursthouse、William Clegg、Luca Russo
DOI:10.1016/j.jorganchem.2009.01.049
日期:2009.6
nickel bromide (6) metal centre. The ring-locked ferrocene complexes produced 2,5′-bis-(acetal)-1,1′-diphenylphosphinoferrocene substitution patterns. The acetal protecting groups of 2,2′-bis-(acetal)-1,1′-diphenylphosphinoferrocene were removed to produce 1,1′-bis-carboxaldehyde-2,2′-diphenylphosphinoferrocene (4). The Cp rings of 1,1′-bisacetalferrocene were also further derivatised at the 2,2′ positions