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The field of bioorthogonal chemistry is rapidly growing, presenting successful applications of organic and transition metal‐catalysed reactions in cells and living systems (in vivo). The development of such reactions typically proceeds through many iterative steps focused on biocompatibility and fast reaction kinetics to ensure product formation. However, obtaining kinetic data, even under simulated biological (biomimetic) conditions, remains a challenge due to substantial concentrations of salts and biomolecules hampering the use of typically employed solution‐phase analytical techniques. In this study, we explored the suitability of gas evolution as a probe to study kinetics under biomimetic conditions. As proof of concept, we show that the progress of two transition metal‐catalysed bioorthogonal chemical reactions can be accurately monitored, regardless of the complexity of the medium. As such, we introduce a protocol to gain more insight into the performance of a catalytic system under biomimetic conditions to further progress iterative catalyst development for in vivo applications. [ABSTRACT FROM AUTHOR]

Performing transition metal‐catalyzed reactions in cells and living systems has equipped scientists with a toolbox to study biological processes and release drugs on demand. Thus far, an impressive scope of reactions has been performed in these settings, but many are yet to be introduced. Nitrene transfer presents a rather unexplored new‐to‐nature reaction. The reaction products are frequently encountered motifs in pharmaceuticals, presenting opportunities for the controlled, intracellular synthesis of drugs. Hence, we explored the transition metal‐catalyzed sulfimidation reaction in water for future in vivo application. Two Cu(I) complexes containing trispyrazolylborate ligands (Tpx) were selected, and the catalytic system was evaluated with the aid of three fitness factors. The excellent nitrene transfer reactivity and high chemoselectivity of the catalysts, coupled with good biomolecule compatibility, successfully enabled the sulfimidation of thioethers in aqueous media. We envision that this copper‐catalyzed sulfimidation reaction could be an interesting starting point to unlock the potential of nitrene transfer catalysis in vivo. [ABSTRACT FROM AUTHOR]

A supramolecular photovoltaic strategy is applied to enhance power conversion efficiencies (PCE) of photoelectrochemical devices by suppressing electron–hole recombination after photoinduced electron transfer (PET). Here, the author exploit supramolecular localization of the redox mediator—in close proximity to the dye—through a rotaxane topology, reducing electron–hole recombination in p‐type dye‐sensitized solar cells (p‐DSSCs). Dye PRotaxane features 1,5‐dioxynaphthalene recognition sites (DNP‐arms) with a mechanically‐interlocked macrocyclic redox mediator naphthalene diimide macrocycle (3‐NDI‐ring), stoppering synthetically via click chemistry. The control molecule PStopper has stoppered DNP‐arms, preventing rotaxane formation with the 3‐NDI‐ring. Transient absorption and time‐resolved fluorescence spectroscopy studies show ultrafast (211 ± 7 fs and 2.92 ± 0.05 ps) PET from the dye‐moiety of PRotaxane to its mechanically interlocked 3‐NDI‐ring‐acceptor, slowing down the electron–hole recombination on NiO surfaces compared to the analogue. p‐DSSCs employing PRotaxane (PCE = 0.07%) demonstrate a 30% PCE increase compared to PStopper (PCE = 0.05%) devices, combining enhancements in both open‐circuit voltages (VOC = 0.43 vs 0.36 V) and short‐circuit photocurrent density (JSC = −0.39 vs −0.34 mA cm−2). Electrochemical impedance spectroscopy shows that PRotaxane devices exhibit hole lifetimes (τh) approaching 1 s, a 16‐fold improvement compared to traditional I−/I3−‐based systems (τh = 50 ms), demonstrating the benefits obtained upon nanoengineering of interfacial dye‐regeneration at the photocathode. [ABSTRACT FROM AUTHOR]

Electrophotocatalytic transformations are garnering attention in organic synthesis, particularly for accessing reactive intermediates under mild conditions. Moving these methodologies to continuous‐flow systems, or flow ElectroPhotoCatalysis (f‐EPC), showcases potential for scalable processes due to enhanced irradiation, increased electrode surface, and improved mixing of the reaction mixture. Traditional methods sequentially link photochemical and electrochemical reactions, using flow reactors connected in series, yet struggle to accommodate reactive transient species. In this study, we introduce a new flow reactor concept for electrophotocatalysis (EPC) that simultaneously utilizes photons and electrons. The reactor is designed with a transparent electrode and employs cost‐effective materials. We used this technology to develop an efficient process for electrophotocatalytic heteroarylation of C(sp3)−H bonds. Importantly, the same setup can also facilitate purely electrochemical and photochemical transformations. This reactor represents a significant advancement in electrophotocatalysis, providing a framework for its application in flow for complex synthetic transformations. [ABSTRACT FROM AUTHOR]

We show that the incorporation of a biotinylated Co(TAML) cofactor within streptavidin enables asymmetric radical-type oxygen atom transfer catalysis with improved activity and enantioselectivity. [ABSTRACT FROM AUTHOR]

The excellent catalytic performances of enzymes in terms of activity and selectivity are an inspiration for synthetic chemists and this has resulted in the development of synthetic containers for supramolecular catalysis. In such containers the local environment and pre‐organization of catalysts and substrates leads to control of the activity and selectivity of the catalyst. Herein we report a supramolecular strategy to encapsulate single catalysts in a urea‐functionalized Fe4L6 cage, which can co‐encapsulate a functionalized urea substrate through hydrogen bonding. Distinguished selectivity is obtained, imposed by the cage as site isolation only allows catalysis through π activation of the substrate and as a result the selectivity is independent of catalyst concentration. The encapsulated catalyst is more active than the free analogue, an effect that can be ascribed to transitionstate stabilization rather than substrate pre‐organization, as revealed by the MM kinetic data. The simple strategy reported here is expected to be of general use in many reactions, for which the catalyst can be functionalized with a sulfonate group required for encapsulation. [ABSTRACT FROM AUTHOR]

The thermal curing of industrial coatings (e.g., car painting and metal coil coatings) is accompanied by a substantial energy consumption due to the intrinsically high temperatures required during the curing process. Therefore, the development of new photochemical curing processes—preferably using visible light—is in high demand. This work describes new diazo‐based cross‐linkers that can be used to photocure acrylic coatings using blue light. This work demonstrates that the structure of the tethered diazo compounds influences the cross‐linking efficiency, finding that side reactions are suppressed upon engineering greater molecular flexibility. Importantly, this work shows that these diazo compounds can be employed as either thermal or photochemical cross‐linkers, exhibiting identical crosslinking performances. The performance of diazo‐cross‐linked coatings is evaluated to reveal excellent water resistance and demonstrably similar material properties to UV‐cured acrylates. These studies pave the way for further usage of diazo‐functionalized cross‐linkers in the curing of paints and coatings. [ABSTRACT FROM AUTHOR]

The group of Costa Figueiredo reported Cu-based catalysts for the electrosynthesis of ammonia from nitrate, and X-ray photoelectron spectroscopy demonstrated that Cu(0) is the active phase during catalysis. The Hamlin and Bickelhaupt group performed high level quantum chemical analysis, showing that C(spn)-halogen bonds are easier to activate by a palladium catalyst when the halogen is larger, due to a difference in activation strain and a more favorable electrostatic attraction between the palladium catalyst and the substrate. The importance of catalysis has been recognized a long time ago and the first industrial application stems from the early nineteenth century. We develop new catalytic processes based on 1) rational ligand design in transition metal catalysis 2) Supramolecular catalysis 3) Bio-inspired catalysis. [Extracted from the article]

An azobenzene-bearing N-heterocyclic carbene-based gold catalyst is reported of which the reactivity in a cyclization reaction depends on the isomeric state of the azobenzene. The configurations of the catalyst can be reversibly switched by light and are stable during the reaction, effectively leading to a switchable catalyst system. [ABSTRACT FROM AUTHOR]