The synthesis and structures of 1,1′-bis(sulfonyl)ferrocene derivatives

Abstract

A series of 1,1′-bis(sulfonyl)ferrocene compounds were produced via the 1,1′-bis(sulfonate)ferrocene ammonium salt. This compound can be readily converted to 1,1′ bis(sulfonylchloride)ferrocene. Varying stoichiometry and reaction times, both mono- and bis-sulfonamide derivatives can be synthesized. All new compounds presented in this report have been structurally characterized. The structures of the bis-sulfonamide systems are similar to the well-studied bis(amide) ferrocene compounds. Intermolecular hydrogen bonding is observed, typically between NH and SO groups of neighboring sulfonamides. However in the bis(GABA) derivative, intermolecular NH to CO hydrogen bonding interactions are present.

New 1,1’-Ferrocene Bis(sulfonyl) Reagents

“…As we were investigating the amino acid chemistry of compound 1 , we observed an unusual reaction with glycine methyl ester. For most primary amines, we observe either the formation of mono or bi‐functionalized ferrocene sulfonamides . However in the case of glycine methyl ester, we observed the formation of a [3]ferrocenophane, compound 5 .…”

“…1,1’‐Bis(sulfonylchloride) ferrocene 1 can be readily generated in three steps from ferrocene via reaction with chlorosulfonic acid, isolation as the ammonium salt, and then reaction with PCl 5 . Previously, we have shown that 1 can be used to generate both mono‐ and bis(sulfonamide) derivatives . The sulfonyl chloride is useful in that it exhibits selectivity in reactivity with amines under wet (i. e. non‐dried) conditions, however reactions with amines frequently requires higher temperatures or extended reaction times.…”

“…Recently, we have started to explore bis(sulfonamide) based conjugates to examine differences from the amide based complexes . In this communication, we examine alternative methods to 1,1’‐ferrocene bis(sulfonamides) derived from 1,1’‐bis(sulfonylchloride)ferrocene, including the bis(sulfonylhydrazide), bis(sulfonylbromide) and bis(sufonylhydroxybenzatriazole) modified ferrocenes.…”

Cation‐Anion Redox Switching in an All‐Ferrocene Salt

“…Among transition metal‐based compounds, ferrocenes have many notable properties as RFB components, ranging from their relative low cost and ease of synthesis to their stabilities and electrochemical reversibility in a variety of media. As part of our continuing investigations into the synthetic modification of ferrocene, we have produced an “all ferrocene” salt (compound 1 , Figure ) comprised of two (ferrocenylmethyl)trimethylammonium cations and a 1,1’‐bis(sulfonate)ferrocene dianion. We observed that this compound exhibits switching of the redox potentials between the cation and anion depending on solution conditions, completely reversing the order in which the cation and anion are oxidized.…”

Administration of ferrocene‐modified amino acids induces changes in synaptic transmission in the CA1 area of the hippocampus

“…Starting from ferrocenyl alcohols FcCH (OH)R and ethyl esters of glycine and β‐alanine under acidic catalysis in aqueous organic medium the corresponding products were obtained . Recently Ziegler and co‐workers elaborated new synthetic route to ferrocene complexes of such type using a sulfonamide linking strategy . Ferrocene‐based pyrazole‐containing amino acids were successfully prepared by Vukićević and co‐workers, and evaluated as promising antitumor agents .…”