An Efficient Asymmetric Synthesis of 2-Substituted Ferrocenecarboxaldehydes

Abstract

Ferrocenecarboxaldehyde is readily transformed into the acetal of (S)-1,2,4-butanetriol (1,3-dioxane structure) and further methylated to give acetal 15. This can then be ortho-lithiated using t-BuLi with very high diastereoselectivity (98% de). Electrophilic quenching provided a large array of compounds of established stereochemistry. Controlled hydrolysis leads to many ortho-substituted ferrocenecarboxaldehydes (98% ee) which themselves are starting materials in the synthesis of various classes of enantiopure ferrocene derivatives with planar chirality of predictable absolute configuration.

Synthesis, reactivity, and some photochemistry of ortho-N,N-dimethylaminomethyl substituted aryl and ferrocenyl pentamethylcyclopentadienyl dicarbonyl iron complexes

“…In accordance with literature reports for these type of substrates [40,52,53], N,N-dimethylaminomethylferrocene methiodide (17) was formed in high yield (84 %), but together with a small amount of methoxymethylferrocene (18, 14 % isolated yield). This proves that methanolysis of the ammonium salt 17 occurs under these reaction conditions but is a slow process.…”

Single-nucleotide polymorphism detection with “wire-like” DNA probes that display quasi “on–off” digital action

“…The corresponding phosphoramidite of the nucleoside analogue for solid-phase DNA synthesis was easily prepared from known ( p S)-2-iodoferrocenecarboxaldehyde 25 (26), and the procedures are shown in Scheme 1 and Supporting Text, which are published as supporting information on the PNAS web site. Other materials were all commercially available.…”

Ferrocene-derived P,N ligands: synthesis and application in enantioselective catalysis

“…Since the original work of Ugi, several other chiral ortho -directing groups have been developed, such as sulfoxides [31], acetals [32,33], sulfoximines [34], hydrazones [35,36], pyrrolidines [37], imidazolines [38], azepines [39], O-methylephedrine derivatives [40], alcohols [41], phosphine oxides [42] and oxazophospholidines [43]. In addition, oxazolines have been shown by various groups to be excellent ortho -directing groups [44][45][46][47].…”