Ferrocene carboxaldehyde derivatives

The second-generation 02" biosensors are mainly based on the electron transfer of SOD shuttled by surface-confined or solution-phase mediators, as shown in Scheme 2(b). In 1995, Ohsaka et al. found that methyl viologen could efficiently shuttle the electron transfer between SOD and the glassy carbon electrode and proposed that such a protocol could be useful for developing 02 biosensors [125], Recently, Endo et al. reported an 02, biosensor based on mediated electrochemistry of SOD [148], In that case, ferrocene-carboxaldehyde was used as the mediator for the redox process of SOD. The as-developed 02 biosensor showed a high sensitivity, reproducibility, and durability. A good linearity was obtained in the range of 0 100 pM. In the flow cell system, tissue-derived 02 was measured. 

Another approach of broader applicability has been described recently. We prepared the chiral acetal 12a derived from ferrocene carboxaldehyde and (S)-l,2,S-butane triol (Figure 10) This acetal was 0-methylated into 12b.The overall yield of 12b from ferrocene carboxaldehyde is about 70%. The structure was established by nmr. 

Ferrocene also undergoes the Vilsmeier reaction to yield ferrocene-carboxaldehyde, which is a useful starting material for the synthesis of other ferrocene derivatives, for example by condensation with compounds containing active CH2 groups such as malonic acid ... 

Aydemir and co-workers used chiral aminoalcohols to prepare phosphinites 118a-b (Scheme 30), through the reaction of the aminoalcohols with ferrocene carboxaldehyde, followed by reaction with chlorodiphenylphosphine. The ligands were tested in ruthenium(ii)-catalysed transfer hydrogenation of acetophenone derivatives, using isopropanol as the hydrogen source, with high conversions and enan-tioselectivities of up to 85% ee. 

The fluorenyl-ferrocene based NLO-phores have were prepared by condensing 2-bromo-, 2,7-dibromofluorene, and 2-nitrofluorene with ferrocene carboxaldehyde to afford 2a, 3a, and 4, respectively, all in reasonable yidd. For 2-nitrofluorene the base used is potassium tert-butoxide and for the bromofluorenes, lithium diisopropylamide (LDA). Complexes 2a and 3a undergo clean halogen-metal exchange Ity treatment with n-BuLi in tetrahydrofiiran (THF) at -78 °C and are thm converted to their respective carboxaldehyde and tributylstannyl derivatives by... 

The NH2 groups in the A-methylhydrazine derivatives (153-157) have been reacted with ferrocene-2-carboxaldehyde (FcCHO, Fc=ferrocenyl) to yield the corresponding hydrazones (158-162). Electrochemical studies of these compounds reveal only a single reversible oxidation pattern, pointing to an electrochemical equivalence of the ferrocenyl groups. 

A polyamino carbonyl ferrocene dmivative formed by coupling ferrocene carboxylic acid with a BOC protected polyamine is claimed to be a mammalian excitatory neurotransmitter antagonist. Ferrocenyltetrazolylhydrozones have been prqrared from the condensation reaction of ferrocenecarboxaldehyde with a series of tetrazolylhydrazines. The reaction of ferrocoie carboxaldehyde with CH2(COR)(COR ), R = Me, R = Me, OEt in ether containing a Lewis base results in the formation of FcCH=C(COR)COR (mixture of E and Z isomers the work is extendable to diferrocenyl derivatives. Further work on the reduction of fluorine substituted methyl acetylferrocenes has been reported. "... 

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