Volume 15 Issue 3, March 2023

Matthew Horwitz, creator of the Synthesis Workshop video podcast, talks to Nature Chemistry about using podcasting as a driver of professional-level education in the chemistry community.

Organolithium reagents are characterized by their high reactivity towards air and moisture, traditionally requiring strict inert conditions for their handling and utilization. Now, these reagents can be encapsulated within an organogel, enhancing their stability and allowing their use and storage under ambient conditions.

The adiabatic approximation is often applied to describe the scattering of molecules or atoms from solid surfaces. Now, unusual energy loss has been observed during the scattering of hyperthermal hydrogen atoms from a single crystalline Ge(111) surface — suggesting the existence of a non-adiabatic mechanism involving electronic interband transitions in the Ge that are induced by the hydrogen atoms.

Mechanical force has recently become a new tool for chemists to create colours, trigger reactions, and develop advanced fabrication techniques not possible using other methods. Force-induced multiple colouring has now been developed as a printing technique in soft lithography, enabling the colouring of polymeric materials without inks.

Kemi Oloyede reflects on the importance of having LGBTQ+ STEM events, and their role in combatting inertia in the scientific community.

Enzymes with identical sequences of amino acids can display varying activities when encoded with mRNA with different properties, but why this is the case has been a mystery. Now, it has been shown that synonymous mutations in mRNA alter the partitioning of proteins into long-lived soluble misfolded states with varying activities.

Organolithium compounds are important reagents but are often hazardous due to their high reactivity. Now, encapsulating organolithium reagents within a supramolecular organogel has been found to enhance their stability, facilitating their storage and handling under ambient conditions. The homogeneous gels can be easily subdivided and dosed into a wide range of synthetic reactions.

Inelastic hydrogen atom scattering from surfaces provides a good benchmark for the validity of the Born–Oppenheimer approximation in surface chemistry. Now it has been shown that hydrogen atoms colliding with a semiconductor surface can efficiently excite electrons above the surface bandgap, representing a clear example of the failure of the approximation.

Mechanochemical generation of dyes with different photophysical properties generally requires the use of discrete mechanophore derivatives with unique chemical structures. Now it has been shown that diverse donor–acceptor Stenhouse adducts can be produced via a mechanically gated chromogenic reaction, enabling mechanochemical multicolour lithography.

Principles of quantum interference can guide the design of chromophores that undergo singlet fission. Now, ‘pencil and paper’ graphical models can be used to understand and predict the dynamics of triplet pairs generated through singlet fission in bridged dimers.

Aromaticity is a ubiquitous concept in organic chemistry yet it is less widespread for inorganic species. Now the cluster [(CpRu)₃Bi₆]^–, obtained as part of a soluble salt, has been shown to exhibit aromatic behaviour referred to as φ-type, owing to a highly regular {Bi₆} substructure causing a non-localizable molecular orbital of \(f_{z^3}\)-like symmetry.

Direct oxidative methods for the enantioselective synthesis of heterobiaryl compounds that exhibit axial chirality remain elusive. Now, the use of an iron catalyst in the presence of a chiral PyBOX ligand and an oxidant enables the direct coupling of naphthols and indoles with high levels of enantio- and cross-selectivity.

The synthesis of cyclic polymers remains challenging. Now a trifunctional B-P-B frustrated Lewis pair has been shown to enable easy access to cyclic acrylic polymers through a bimolecular mechanism. These cyclic polymers have enhanced thermodynamic properties compared with their linear counterparts, while maintaining high chemical recyclability.

Neutral homoaromatic hydrocarbons—which possess an interrupted π-system yet display aromatic properties owing to through-space or through-bond interactions—have remained rare as they are typically unstable. Now a class of stable neutral homoaromatic homoannulenes has been synthesized, including one that acts as a photoswitch through a reversible [1, 11] sigmatropic rearrangement.

The strong regiochemical preferences of electrophilic aromatic substitution have played a key role in defining the diversity of accessible chemical space. Now, it has been shown that the electrophilic arylation of phenols can be achieved at the electronically disfavoured meta-position via a formal 1,2-migration of a key σ-complex intermediate.

Heteroatom–heteroatom cross-couplings have so far remained elusive. Now, a copper-catalysed enantioselective S–O cross-coupling of diverse diols or triols with sulfonyl chlorides has been realized via a single-electron reductive elimination manifold. The reaction provides access to value-added chiral C₃ building blocks and inositol phosphates through enantioselective desymmetrization of biomass-derived alcohols.

The enantioselective functionalization of C₆₀ is highly challenging, typically requiring complex chiral tethers or demanding chromatography. Fullerenes have now been shown to undergo Diels–Alder reactions in a chemo-, regio- and enantio-selective fashion through confinement within an enantiopure metal–organic cage functionalized with a chiral formylpyridine group.

Interlocked shape-persistent organic cages are rare structures and the majority are formed using π-stacking as the driving force. Now it is shown that weak dispersion interactions—which are modulated by changing the 1,4-substituents of the constituent dialdehyde linkers—can be used to form interlocked dimeric and trimeric catenated cages.

Asymmetric systems for catalytic carbohydrate functionalization are mostly limited to chiral copper complexes and organocatalysts. Now, a synergistic chiral Rh(I)- and organoboron-catalysed site-selective functionalization of carbohydrate polyols has been developed, giving stereocontrolled access to biologically relevant arylhydronaphthalene glycosides. Enantio-, diastereo-, regio- and anomeric control and dynamic kinetic resolution were found to be concomitantly operative.

Rahul Dev Mukhopadhyay and Kimoon Kim consider how cucurbiturils — pumpkin-shaped macrocycles — went from curiosities to compelling cavitands for a host of applications.