Helical Chirality of Ferrocene Moieties in Cyclic Ferrocene‐Peptide Conjugates
Toshiyuki Moriuchi
Abstract
Abstract Ferrocene has been utilized as an organometallic scaffold for more than 25 years, serving as a central reverse‐turn unit with the inter‐ring spacing of about 3.3 Å. A variety of ferrocene‐peptide conjugates have been designed to construct protein secondary structures and demonstrate the chirality organization via hydrogen bonding. In general, the helical chirality of ferrocene moieties in acyclic ferrocene‐peptide conjugates is induced by the absolute configuration of the α ‐carbon atom of an amino acid adjacent to the ferrocene unit. Cyclization regulations restrict conformational flexibility of the peptide chains, inducing inversion of the helical chirality based on the reordering of the hydrogen bonding interactions. In this Minireview article, the helical chirality of ferrocene moieties in cyclic ferrocene‐peptide conjugates is focused on. Controlled helical chirality of ferrocene moieties in a series of ferrocene‐peptide conjugates by adjusting conformational flexibility of the peptide chains through cyclization regulations is introduced.