The synthesis of [2]catenanes by single macrocyclization and double macrocyclization strategies using Cu(I) ions to catalyze covalent bond formation while simultaneously acting as the template for the mechanically interlocked structure is reported. These "active metal template" strategies employ appropriately functionalized pyridine ether or bipyridine ligands and either the CuAAC "click" reaction of azides with terminal alkynes or the Cu(I)-mediated Cadiot-Chodkiewicz heterocoupling of an alkyne halide with a terminal alkyne. Using one macrocyclic and one acyclic building block, heterocircuit (the rings are constitutionally different) [2]catenanes are produced via the single macrocyclization route in up to 53% yield by optimizing the reaction conditions and relative stoichiometry of the starting materials. Alternatively, with the active template CuAAC reaction, a single acyclic unit can be used to form a homocircuit (two identical rings) [2]catenane in 46% yield through a one-pot, double macrocyclization, procedure. Remarkably, <7% of the corresponding noninterlocked macrocycle is isolated from this reaction, indicating the efficacy of Cu(I) as both a template for the catenane and a catalyst for covalent bond formation in the reaction.
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http://dx.doi.org/10.1021/ja9070317 | DOI Listing |
Nat Commun
January 2025
Developmental Therapeutics Branch & Laboratory of Molecular Pharmacology, Center for Cancer Research, National Cancer Institute, NIH, Bethesda, MD, USA.
Type IA topoisomerases (TopoIAs) are present in all living organisms. They resolve DNA/RNA catenanes, knots and supercoils by breaking and rejoining single-stranded DNA/RNA segments and allowing the passage of another nucleic acid segment through the break. Topoisomerase III-β (TOP3B), the only RNA topoisomerase in metazoans, promotes R-loop disassembly and translation of mRNAs.
View Article and Find Full Text PDFChem Rev
January 2025
Yusuf Hamied Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, United Kingdom.
Template-directed synthesis has become a powerful methodology to access complex molecules. Noncovalent templating has been widely used in the last few decades, but less attention has been paid to covalent template-directed synthesis, despite the fact that this methodology was used for the first reported synthesis of a catenane. This review highlights the evolution of covalent templating over the last 60 years, thereby providing a toolbox for the design of efficient covalent templating processes.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
January 2025
College of Chemistry and Molecular Sciences, Henan University, Kaifeng, 475004, China.
Cycloparaphenylenes (CPPs) represent a significant challenge for the synthesis of mechanically interlocked architectures, because they lack heteroatoms, which precludes traditional active and passive template methods. To circumvent this problem and explore the fundamental and functional properties of CPP rotaxanes and catenanes, researchers have resorted to unusual non-covalent and even to labor-intensive covalent template approaches. Herein, we report a ring-in-ring non-covalent template strategy that makes use of the surprisingly strong non-covalent inclusion of crown ethers into suitably sized CPPs.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
December 2024
College of Chemistry and Chemical Engineering, Luoyang Normal University, Henan Province Function-Oriented Porous Materials Key Laboratory, Luoyang, 471934, P. R. China.
The synthesis of high-ordered mechanically interlocked supramolecular structures is an extremely challenging topic. Only two linear [4]catenanes have been reported so far and there is no defined strategy to obtain cyclic [4]catenane. Herein, two unprecedented cyclic [4]catenanes, 1 and 2, were prepared in high yields.
View Article and Find Full Text PDFInorg Chem
November 2024
Department of Inorganic and Physical Chemistry, Indian Institute of Science, Bangalore 560012, India.
Synthesis of interlocked supramolecular cages has been a growing field of interest due to their structural diversity. Herein, we report the template-free synthesis of a Ru(II) triply interlocked [2] catenane using coordination-driven self-assembly. The self-assembly of a triazine-based tripyridyl donor (2,4,6-tris(5-(pyridin-4-yl)thiophen-3-yl)-1,3,5-triazine) with a dinuclear Ru(II) acceptor (Ru(dhnq)(η--cymene))(CFSO)) yielded two distinct structures depending on the solvent and concentration.
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