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

Abstract

Several new 1,1′-bis(sulfonyl)ferrocenes designed for the synthesis of sulfonamide linked biological conjugates have been prepared. 1,1′-Bis(sulfonylbromide)ferrocene can be produced from the corresponding sulfonylchloride via a bis(sulfonylhydrazide) intermediate. Bis(sulfonyl-N-hydroxybenzotriazole)ferrocene can also be synthesized from the sulfonyl chloride, and reaction of glycine methyl ester with the sulfonyl chloride affords a [3]ferrocenophane complex. All new compounds have been structurally characterized by X-ray crystallography.

Highly Soluble Imidazolium Ferrocene Bis(sulfonate) Salts for Redox Flow Battery Applications

“…Bis­(ferrocene sulfonic acid) is generated via the reaction of ferrocene and chlorosulfonic acid . Our group has used this reagent in the past to make sulfonamide conjugates containing amino acids and biomolecules as well as various electrochemically active sulfonate salts. − The bis­(ferrocene sulfonic acid) was initially reacted with Ag 2 O to generate silver salts in situ with a subsequent introduction of the imidazolium halide salts to afford pure materials 1 – 6 (Scheme ). The preparation of the silver ferrocene salt was completed first to reduce the generation of silver N-heterocyclic carbenes, as they are classically prepared by reacting imidazolium salts with silver­(I) oxide. , …”

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.…”

Amino acid ferrocene conjugates using sulfonamide linkages

“…However, the compound was obtained in a very low yield in the form of single crystals. The major product from the reaction of 3 and glycine methyl ester was the [3]ferrocenophane, Fc(η 2 -SO 2 ) 2 NGly-OMe, reported previously [27].…”

“…Compounds 4a and 8 were obtained in very low yield as a few single crystals and were not further characterized. Compound 4a resulted from the hydrolysis of 4 , and 8 was produced as a byproduct of the reaction to form the N-glycyl ferrocenophane, on which we have reported previously [27].…”