Herein, we report the facile synthesis and properties of a chiral perylene diimide (PDI)-embedded conjugated macrocycle (cyclo[6]paraphenylene-1,7-perylene diimide, ) by Pd-catalyzed Suzuki coupling and a subsequent reductive aromatization reaction in two steps. The PDI-embedded conjugated macrocycle showed a significant redshift (>110 nm for absorption) compared to the PDI molecule. Moreover, efficient resolution of chiral enantiomers with was achieved by high-performance liquid chromatography, and their chiral properties were investigated by circular dichroism spectroscopy. The realization of expands the scope of the precise synthesis of PDI-embedded chiral conjugated macrocycles and explores its unique physical properties.
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http://dx.doi.org/10.1021/acs.orglett.3c00152 | DOI Listing |
Chem Commun (Camb)
January 2025
Research School of Chemistry, Australian National University, Canberra 2601, ACT, Australia.
A two-step, biocompatible strategy enables site-specific generation of branched and macrocyclic peptide-protein conjugates. Solvent-exposed cysteines on proteins are modified by a small bifunctional reagent at near-physiological pH, followed by cyanopyridine-aminothiol click reactions to create branched or macrocyclic peptide architectures. This method offers design strategies for next-generation protein therapeutics.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
January 2025
National University of Singapore - Kent Ridge Campus: National University of Singapore, Department of Chemistry, Faculty of Science, 3 Science Drive 3, 117543, Singapore, SINGAPORE.
Figure-eight macrocycles represent a fascinating class of π-conjugated units characterized by unique aesthetics and non-contact molecular crossing at the center. Despite progress in synthesis over the past century, research into inorganic, organic, and polymeric figure-eight materials remains in its infancy. Here we report the first examples of figure-eight covalent organic frameworks by condensing figure-eight knots to create extended porous figure-eight π architectures.
View Article and Find Full Text PDFNat Commun
January 2025
College of Polymer Science and Engineering, State Key Laboratory of Polymer Materials Engineering, Sichuan University, 610065 Chengdu, China.
Dual-atom catalysts featuring synergetic dinuclear active sites, have the potential of breaking the linear scaling relationship of the well-established single-atom catalysts for oxygen reduction reaction; however, the design of dual-atom catalysts with rationalized local microenvironment for high activity and selectivity remains a great challenge. Here we design a bisalphen ladder polymer with well-defined densely populated binuclear cobalt sites on Ketjenblack substrates. The strong electron coupling effect between the fully-conjugated ladder structure and carbon substrates enhances the electron transfer between the cobalt center and oxygen intermediates, inducing the low-to-high spin transition for the 3d electron of Co(II).
View Article and Find Full Text PDFPhotosynth Res
January 2025
Graduate School of Life Sciences, Ritsumeikan University, Kusatsu, Shiga, 525-8577, Japan.
Pheophytin-a derivatives possessing plastoquinone and phylloquinone analogs in the peripheral 3-substituent were prepared by Friedel-Crafts reactions of a 3-hydroxymethyl-chlorin as one of the chlorophyll-a derivatives with benzo- and naphthohydroquinones, respectively, and successive oxidation of the 1,4-dihydroxy-aryl groups in the resulting dehydration products. The 3-quinonylmethyl-chlorins exhibited ultraviolet-visible absorption and circular dichroism spectra in acetonitrile, which were composed of those of the starting 3-hydroxymethyl-chlorin and the corresponding methylated benzo- and naphthoquinones. No intramolecular interaction between the chlorin and quinone π-systems was observed in the solution owing to the methylene spacer.
View Article and Find Full Text PDFChemistry
January 2025
Research School of Chemistry, Australian National University, Canberra, ACT, 2601, Australia.
Constrained peptides possess excellent properties for identifying lead compounds in drug discovery. While it has become increasingly straightforward to discover selective high-affinity peptide ligands, especially through genetically encoded libraries, their stability and bioavailability remain significant challenges. By integrating macrocyclization chemistry with bismuth binding, we generated series of linear, cyclic, bicyclic, and tricyclic peptides with identical sequences.
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