Reaction mechanisms articles from across Nature Portfolio

Sulfur(vi) fluoride exchange and modular diazotransfer reactions have advanced click chemistry, but their mechanisms and reactivity profiles are not well understood. Now, a computational study of these reactions provides mechanistic insights and predictive reactivity models for modular diazotransfer, facilitating the development of an easy-to-prepare and -handle diazotransfer reagent with excellent reactivity.

Computational analysis of competing sulfur(VI)–fluoride exchange and modular diazotransfer pathways in the reaction between primary amines and fluorosulfuryl azide reveals that diazotransfer is more kinetically and thermodynamically favoured. Predictive models are formulated by combining mechanistic analysis and structure–activity relationship studies, enabling the development of an easy-to-prepare and highly reactive diazotransfer reagent.

Nickel-catalyzed C–H bond functionalization reactions provide an impressive alternative to those with noble metal catalysts but the regioselective C(sp²)−H borylation reaction of arenes accomplished by nickel catalyst remains challenging. Here the authors disclose a silyl-directed ortho C(sp²)−H borylation of substituted arenes with a Ni(cod)₂/PMe₃/KHMDS catalyst system.

The Friedel–Crafts reaction is one of the most well-known methods available to organic chemists, but Friedel–Crafts methylation of arenes is generally not effective. Here, the authors use an HF/SbF5 superacid system to generate an arenium ion, which enables meta-selective methylation after a rearrangement.

Several methodologies have been proposed for hydroboration of cyclopropanes by activating C–C bonds, conventionally relying on noble and hazardous metal catalysts to control reaction outcomes. Here, the authors report a strategy for crafting stereochemically precise γ-borylenamides through ring-opening of cyclopropanes without metallic entities.

Suzuki–Miyaura cross-coupling between (hetero)aryl (pseudo)halides and base-sensitive and Lewis-basic (hetero)arylboronic acids is challenging, owing to potential side reactions and catalyst poisoning. Now, the Suzuki–Miyaura cross-coupling of arylthianthrenium salts with (hetero)arylboronic acids, under acidic conditions, is reported, enabling the efficient coupling of base-sensitive and Lewis-basic (hetero)arylboronic acids.

Sulfur(vi) fluoride exchange and modular diazotransfer reactions have advanced click chemistry, but their mechanisms and reactivity profiles are not well understood. Now, a computational study of these reactions provides mechanistic insights and predictive reactivity models for modular diazotransfer, facilitating the development of an easy-to-prepare and -handle diazotransfer reagent with excellent reactivity.

The stereoselectivity of S_N1-type glycosylation reactions involving 4,6-O-benzylidene-protected sugars is determined by a glycosyl cation intermediate. However, these species are usually too unstable to be characterized directly in solution. Now, mass spectrometry is used to capture these ions in a vacuum and to analyse their structure using cryogenic infrared spectroscopy, in conjunction with computational calculations.

A strategy for the cobalt-hydride-catalysed enantioselective hydroalkylation of 1,1-disubstituted styrenes is demonstrated, enabling the efficient construction of chiral tertiary carbon centres at the benzyl position. This method overcomes the requirement for a heteroatom-containing substrate, with enantiocontrol instead achieved through C–H···π interactions between the substrate and catalyst.

Carbenes are reactive intermediates that undergo many useful transformations yet are typically accessed via functionalized precursors and often require additives. Now, shelf-stable alkynes have been used to generate metal-free carbenes in an additive- and by-product-free method that rapidly affords diverse heterocyclic frameworks.

The optimization of chemical reactions can be laborious, particularly in the case of complex, multicomponent catalytic cycles. Now, it is shown that Bayesian optimization methods, underpinned by explainable computational physical models, can guide chemists to discover efficient organic molecular metallophotocatalyst formulations, avoiding the use of precious metals such as iridium.