Nuestros compañeros Alberto Concellón, Jesús Mosquera y Jorge Reñé, miembros de la RSEQ, han sido receptores de una beca Leonardo de la Fundación BBVA. Las Becas Leonardo de Investigación Científica…

No need for metals or recognition sites to build these molecular machines

Biological adaptive receptors are driven out of equilibrium to change the detectable range of analyte concentrations. Here, a chemically fueled rotaxane information ratchet couples Zn(II) binding to c...

The structural anisotropy necessary for the powered directional rotation of chemically fuelled molecular motors had previously been provided by chiral fuels or enzymes. Now it has been shown that asym...

Molecular machine properties such as speed, efficiency, power, and torque depend upon particular features of structure, mechanism, and chemistry. The graphical abstract shows a Top Trumps-style repres...

Control of tetrazine-mediated inverse electron demand Diels–Alder (IEDDA) reaction has been achieved by rotaxanation. Tetrazine rotaxanes were synthesized in high yield and they displayed a much slow...

Heterocycles dramatically change the performance of hydrazone photoswitches. Basic rings cause rapid thermal isomerization via tautomerization, while ones that can participate in H-bonding lower swit...

We report the deletion of nitrogen atoms from multiple template sites in rotaxanes, catenanes, and a molecular knot. Nitrogen extrusion from secondary amines in the backbone of the interlocked structures is achieved using O-diphenylphosphinylhydroxylamine (DPPH), forming carbon–carbon bonds while largely maintaining the integrity of the original mechanical bonding. We find that DPPH gives improved yields (up to 51%) for nitrogen atom deletions from template sites in rotaxanes compared to an anomeric amide nitrogen-deletion reagent and overcomes a major substrate limitation in that, using DPPH, only one of the substituents of the secondary amine in the rotaxane axle needs to be radical-stabilizing. Multiple template site nitrogen atom deletions were accomplished from a range of mechanically interlocked architectures, despite the potential for dethreading, unlinking, and/or strand uncrossing during each successive deletion event. Highlights include the deletion of two template sites from a doubly threaded [3]rotaxane (37% yield) and [3]catenane (45%), quadruple N-deletion of amines from both rings of a [2]catenane (33%), and six N-deletions from the six amine groups in a molecular trefoil knot (7%). The combination of skeletal editing with template synthesis provides a general strategy for synthesis that significantly increases the structural diversity of interlocked molecules that are potentially accessible.

Among the variety of synthetically useful isocyanides, 2-isocyanoanilines have been scarcely reported in the chemical literature, despite the rich chemistry that expectedly could derive from the react...

The discovery and development of artificial catalysts to carry out bioorthogonal reactions in living cells is a primary goal at the interface of Chemistry and Biology. Current approaches rely on time-...

Aromatic oligoamides, with their intrinsic rigidity and well-defined conformations, are recognized for their potential in medical applications. Similar structures are present in several naturally occurring antibiotics and have been explored for their ability to bind to various proteins and B-DNA (canonical right-handed DNA helix). This study introduces a synthetic approach to produce quinoline amino acid monomers bearing diversified side chain combinations in positions 4, 5, and 6 of the quinoline ring, designed to enhance the side chain density on helical foldamers. By increasing the number of side chains on each monomer, we aim to mimic the dense side chain presentation of α-peptides, thus improving the potential for protein surface recognition. This synthetic strategy involves efficient functionalization through cross-coupling reactions, enabling the installation of diverse side chains at strategic positions on the quinoline ring. The process has been optimized for automated solid-phase synthesis, successfully producing a 20-unit oligoamide with good purity. This foldamer, featuring multiple cationic, anionic, polar, and hydrophobic side chains, demonstrates the potential for molecular recognition in drug discovery and therapeutic applications. The methodology described here represents a significant advancement in the construction of aromatic oligoamide foldamers, providing a robust platform for further exploration of biological systems.

Despite significant interest in conjugated polymers for a wide range of applications in electronics, n-type materials have lagged in performance relative to their p-type counterparts. Polyacetylene is a promising scaffold for addressing this deficiency, as the most conductive conjugated polymer to date when p-doped. However, it displays orders of magnitude lower conductivity in the n-doped state and is not stable under ambient conditions. The systematic introduction of electron-withdrawing groups to the backbone could solve this issue, but few such examples exist. Herein, we address this gap by introducing maleimide polyacetylene (mPA) as a new n-type conjugated polymer. The alternating vinylene-maleimide sequence introduces strongly electron-withdrawing groups to the polyacetylene core while retaining backbone planarity, conferring both ambient stability (LUMO = −4.35 eV) and good conductivity (σ = 22 S/cm) in the n-doped state. The versatile synthetic approach uses ring opening metathesis polymerization to generate nonconjugated precursor polymers with low dispersity and controlled molecular weight. These are then converted to mPA by an unusual base-mediated oxidation that leverages the acidity of the maleimide α-protons.

Job Title: Associate or Senior Editor (Organic Chemistry), Nature Communications Organisation: Nature Portfolio Locations: Jersey City, London, New York, Philadelphia or Washington DC - hybrid working...

A mechanochromic rotaxane capable of releasing azetidine-trityl-maleimide (ATM), a new fluorescent probe displaying excellent optical properties (rigidochromic, large Stokes shift, solvent insensitiv...

Measuring individual trajectories during the operation of synthetic devices is crucial for a thorough understanding of this operation. Here, we use op…