Systematizing structural motifs and nomenclature in 1,n′-disubstituted ferrocene peptides

Abstract

Ferrocene peptide conjugates display an array of structural features including helical ferrocene based chirality and a number of different intramolecular hydrogen bonding patterns. In this tutorial review we present a rigorous nomenclature for these systems, followed by a section that summarises and categorises the structures known to date. The issues discussed herein are of general relevance for all metallocene-based chiral transition metal catalysts and peptide turn mimetics.

Oligonuclear Ferrocene Amides: Mixed‐Valent Peptides and Potential Redox‐Switchable Foldamers

“…However, the 1,2' conformation with eight-membered hydrogen-bonded rings is now stabilized by even more than 45 was studied by DFT calculations (Figure 13). First, we note that most hydrogen-bonded conformers ( Figure 6) converge to extended molecules lacking hydrogen bonds during optimization (see Supporting Information).…”

Metal–Carbon Bonds in Biopolymer Conjugates: Bioorganometallic Nucleic Acid Chemistry

“…70 Planar chirality is rare in nature, with very few naturally occurring compounds displaying this type of stereochemistry. However, it is an important consideration in certain organometallic peptide systems 71 although rarer in artificial nucleic acid systems, notwithstanding some recent examples arising as a result of the incorporation of [2.2]paracyclophane 72 and binaphthyl 73 units into DNA. It has also been previously observed in Inouye's ferrocene-tagged DNA systems ( Figure 6).…”

Incorporation of the Unnatural Organometallic Amino Acid 1′‐Aminoferrocene‐1‐carboxylic Acid (Fca) into Oligopeptides by a Combination of Fmoc and Boc Solid‐Phase Synthetic Methods

“…[5] The use of ferrocene-1,1Ј-dicarboxylic acid as a turn inducer was described by several groups, particularly those of Herrick, Hirao and Kraatz. [6][7][8][9][10][11][12][13][14] Ferrocene derivatives bearing parallel podand peptide strands were shown to induce helically ordered structures which are controlled by strong intramolecular hydrogen bonds as shown in the solid state by Xray crystallography studies as well as in solution by IR, 1 H NMR and CD spectroscopy. [7][8][9][10]15,16] In previous work we investigated the role of 1Ј-aminoferrocene-1-carboxylic acid (Fca) as a turn mimetic in the tetrapeptide Boc-Ala-Fca-Ala-Ala-OMe (1) which contains antiparallel peptide strands stabilized by two intramolecular hydrogen bonds in both, solution and solid phases (Scheme 1).…”