N-(ethoxycarbonyl)ferrocenecarboxamide: Synthesis and use as the pronucleophile in the Mitsunobu reaction

The title compound has been synthesized in the reaction of ferrocene with ethoxycarbonyl isocyanate in methanesulfonic acid. It has been found that it undergoes N-alkylation with benzyl alcohols under classical Mitsunobu conditions (PPh3/DEAD). However, in the reaction with cholesterol and stigmasterol O-alkylation with inversion of configuration occurred (confirmed by hydrolysis of the product obtained from cholesterol to epicholesterol). The structure of the product obtained from p-nitrobenzyl alcohol was determined by X-ray diffraction.

Graphical abstractN(ethoxycarbonyl)ferrocenecarboxamide reacts with alcohols under classical Mitsunobu conditions (PPh3/DEAD) to afford, depending on the structure of alcohol, products of N- or O-alkylation.Figure optionsDownload full-size imageDownload as PowerPoint slideHighlights► The submitted paper describes a one-step synthesis of a ferrocenyl amide having an ester subtituent at the nitrogen atom. ► This compound undergoes Mitsunobu reactions with alcohols to afford products of N- or O-alkylation. ► The reaction opens a novel synthetic entry to a variety of ferrocene derivatives. ► It has been used for synthesis of ferrocenyl derivatives of cholesterol and stigmasterol.