Could small-team science be dying out?

The proportion of one- and two-author papers in the Nature Index is shrinking rapidly, as science done by big teams continues to surge.

nature.com

Molecular ratchets: unlocking the chemistry of biological motion

Motor proteins power everything from muscle contraction to bacterial swimming. While replicating their chemically fuelled directional motion in the laboratory has proved difficult, researchers are mak...

chemistryworld.com

The Assault On Science Funding Continues

science.org

Molecular ratchets: unlocking the chemistry of biological motion

Motor proteins power everything from muscle contraction to bacterial swimming. While replicating their chemically fuelled directional motion in the laboratory has proved difficult, researchers are mak...

chemistryworld.com

A simpler way to make rotaxanes

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

cen.acs.org

A simpler way to make rotaxanes

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

cen.acs.org

Latest White House move to politicise science funding provokes outrage among research leaders

US research community mobilising to push back on proposed rule that would give apparatchiks control of which research gets funded

chemistryworld.com

Conformationally Switchable Molecular Trefoil Knot Assembled From 2,6-Bis(1,2,3-triazol-4-yl)pyridine (btp) Building Blocks

We report an efficient lanthanide-template synthesis of a conformationally switchable molecular trefoil knot assembled from three 2,6-bis(1,2,3-triazol-4-yl)pyridine (btp) ligand strands. Coordination of Lu3+ organizes three btp building blocks into a trimeric circular helicate that, upon subsequent ring-closing olefin metathesis, gives a trefoil knotted coordination complex in 73% yield over two steps. Subsequent demetalation with tetraethylammonium fluoride quantitatively affords the corresponding metal-free 87-atom-loop trefoil knot. The metal-coordinated and metal-free knots were characterized by NMR spectroscopy, high-resolution mass spectrometry, and single-crystal X-ray diffraction. The metalated and metal-free knots adopt substantially different conformations to each other, in both solution and the solid state. In the Lu3+-bound knot the btp units are directed inward to coordinate the metal center, with the strand conformation further stabilized by pyridine–naphthalene π-stacking. In the metal-free knot the btp motifs are rotated outward, with the conformation stabilized by triazole C–H···O hydrogen bonding and naphthalene–naphthalene π-stacking. Reversible metalation and demetalation cleanly interconverts the two knot conformations, establishing btp building blocks as a simple and versatile platform for responsive entangled or woven molecular topologies.

pubs.acs.org

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Out-of-equilibrium sensing with a chemically fueled molecular machine

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...

cell.com

Sadiq Khan urges Labour to campaign on rejoining EU at next election

Mayor of London says returning to EU now more desirable because of economic instability caused by Donald Trump Labour should go into the next general election promising to rejoin the EU, Sadiq Khan has said. The mayor of London has repeatedly made the case for joining the customs union and single market, but went much further on Wednesday night by suggesting the party should promise full membership at next ballot. Continue reading...

theguardian.com

Electroreductive Cleavage of C(sp3)–N Bonds in Saturated N-Carbonyl Heterocycles

Ring-opening C–N bond cleavage reactions provide an effective means to convert widespread, readily accessible chiral N-heterocycles into hard-to-attain stereodefined linear amines. Current strategies either rely on the strain-induced release of small aziridine and azetidine rings or, for larger ring systems, require highly electrophilic reagents, oxidative conditions, or preinstalled reactive functionalities to enable the ring-opening event. Recently, complementary radical strategies that exploit the reactivity of α-amino-ketyl radicals, formed upon single-electron transfer (SET) reduction of common N-carbonyl protecting groups, have emerged. Nevertheless, these methods facilitate the homolytic fragmentation only of up to 5-membered azacycles. In this study, we leveraged electroreductive conditions to switch the nature of the above C–N bond cleavage manifold from radical to ionic and enable the heterolytic ring-opening of a broad array of unstrained cyclic amines (comprising pyrrolidines, piperidines, azepines, azocanes, and N-macrocycles), protected as N-(thio)amides, carbamates, or ureas. Crucially, this electrochemically enabled reactivity switch grants complementary functional group compatibility and a broader ring size and N-carbonyl group scope. Computational and experimental studies indicate that electrochemical settings are crucial for generating the Mg(II)-Lewis acid catalyst, activating the N-carbonyl moiety while prompting the so-formed oxy-iminium ion intermediates to undergo two consecutive cathodic SET reductions, generating “umpoled” α-amino-α-oxy-carbanion species. These, via irreversible E1cB fragmentation of the adjacent C–N bond, lead to the desired ring-opened products. Our electrochemical procedure can be scaled up and miniaturized (enabling its application to high-throughput experimentation screening), and its synthetic utility has been demonstrated by accessing decorated stereodefined linear amides from stereochemically rich pyrrolidine and azepane derivatives.

pubs.acs.org

Chiral catalysis-driven rotary molecular motors - Nature Chemistry

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...

nature.com

UK to rejoin EU’s Erasmus student exchange programme

Exclusive: British students will be able to participate in EU-wide scheme from January 2027, sources say

theguardian.com

Reductive radical chain initiation through the thermal generation of carbon dioxide radical anion - Nature Synthesis

Radical chain initiation strategies are fundamental to the synthesis of small molecule drugs and macromolecular materials. Here a general, thermally driven and scalable method for reductive initiation...

nature.com

Acceleration of [2]Catenane Formation by One of its Rings

This highlight underscores the most straightforward synthesis of [2]catenanes from readily available molecular precursors: The one-pot, two-step catenane formation from a crown ether, a linear diamin...

onlinelibrary.wiley.com