Controllable Construction of Vinyl Sulfones and β‐Keto Selenosulfones via Selective Oxidative Sulfonylation of Alkenes

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Controllable Construction of Vinyl Sulfones and β-Keto Selenosulfones via Selective Oxidative Sulfonylation of Alkenes

The selective electrochemical C—H sulfonylation of alkenes with selenium sulfonate was disclosed. Aerobic trifunctionalization of alkenes occurred by simply changing the conditions, which provides diverse β-keto selenosulfones.


Comprehensive Summary

The selective oxidative sulfonylation of alkenes with selenium sulfonate depended on the reaction conditions. The electrochemical C—H sulfonylation proceeded smoothly to afford (E)-vinyl sulfones with good selectivity in an undivided cell without external oxidant. While aerobic trifunctionalization of alkenes occurred in the presence of KI in the air, which provides β-keto selenosulfones via the formation of C—O, C—S, and C—Se bonds in one-pot. Following control experiments, a plausible mechanism is proposed to rationalize the experimental results.

An Efficient Probe for Bacterial Nitroreductase Imaging and Detection Based on NanoLuc‐Furimazine Bioluminescent Pair

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An Efficient Probe for Bacterial Nitroreductase Imaging and Detection Based on NanoLuc-Furimazine Bioluminescent Pair

A panel of furimazine-based bioluminescent probes has been developed for the detection of pathogenic bacterial nitroreductase. The probe containing 2-nitro-N-methyl-imidazolyl possessed up to a 560-fold increment in bioluminescent intensity, with detection limit as low as 16 ng/mL, making it suitable for bioluminescent visualization in vivo.


Comprehensive Summary

The detection of critical endogenous species, such as bacteria in microenvironments in the body, requires better imaging tools for visualization and monitoring of biological events. Bioluminescence imaging is the most popular strategy for obtaining real-time in living cells and organisms. Herein, we introduced a nitroaryl group on the C-3 position and a hydroxy group at the C-6 phenyl ring on furimazine to report the first bioluminescent probe (7) based on NanoLuc-furimazine bioluminescent pair for the detection of nitroreductase in bacteria. The probe, which possessed up to 560-fold intensity increase with a low detection limit of 16 ng/mL of nitroreductase, has the most efficient uncage efficiency in comparison with other bioluminescent congeners, thus enabling highly selective and sensitive visualization of NTR activity in a panel of clinical priority pathogens. Additionally, imaging of the recombinant strain as well as the NTR from mouse feces indicated the potential of this probe in the application of different mouse disease models.

Transition‐Metal‐Free Allylic Defluorination Cross‐Electrophile Coupling Employing Rongalite

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Transition-Metal-Free Allylic Defluorination Cross-Electrophile Coupling Employing Rongalite

A transition-metal-free allylic defluorination reductive cross-coupling between CF3-alkenes and diaryliodonium salts mediated by rongalite has been described for the first time. This procedure was compatible with both linear and cyclic diaryliodonium salts, enabling a wide variety of substrates. The utility of this approach was demonstrated through gram-scale synthesis and efficient late-stage functionalizations of anti-inflammatory drugs.


Comprehensive Summary

The conversion of CF3-alkenes to gem-difluoroalkenes using reductive cross-coupling strategy has received much attention in recent years, however, the use of green and readily available reducing salt to mediate these reactions remains to be explored. In this work, a concise construction of gem-difluoroalkenes, which requires neither a catalyst nor a metal reducing agent, was established. Rongalite, a safe and inexpensive industrial product, was employed as both a radical initiator and reductant. This procedure was compatible with both linear and cyclic diaryliodonium salts, enabling a wide variety of substrates (>70 examples). The utility of this approach was demonstrated through gram-scale synthesis and efficient late-stage functionalizations of anti-inflammatory drugs.

Intra and interatomic energy contributions in the photophysical relaxation of small aromatic molecules

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Intra and interatomic energy contributions in the photophysical relaxation of small aromatic molecules

Based on appropriate PES data, the Interacting Quantum Atoms method (IQA) allows to quantify the atomic and pair contributions that promote the relaxation of an excited electronic state, thus providing mechanistic information useful for rationalising photophysical processes in molecular systems.


Abstract

A theoretical study of the non-radiative photophysical relaxation mechanisms of the first singlet excited state of benzene, cyclobutadiene and fulvene is presented. For these molecules, the calculation of the Minimum Energy Path (MEP) leading from the Franck–Condon region to the surface crossing with the ground state is carried out. Subsequently, the decomposition of the electronic energies into atomic and pair contributions is performed using the Interacting Quantum Atom (IQA) method. The IQA approach provides the important mechanistic information necessary to rationalise some relevant aspects of the processes, such as the components that explain the appearance of an energy barrier or that favour the crossing between potential energy surfaces (PES); it also allows to quantify the direct effect on the MEP due to the inclusion of a substituent. In particular, it is shown how the IQA energies allow measuring the extent to which the formation of biradicaloid structures affects the crossing of the PES. The analysis of electron density functions suggests that aromaticity is not a driving force on the relaxation processes. Overall, this work shows the potential of the IQA method as a useful tool for the detailed description of photophysical processes.

Upcycling Food By‐products: Characteristics and Applications of Nanocellulose

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Upcycling Food By-products: Characteristics and Applications of Nanocellulose

Nanosized cellulose, obtainable from food by-products, has great potential for use in the food industry. This review covers the specific extraction processes for nanocellulose and its various applications, including as a food additive, encapsulation agent, in green packaging, and as a functional coating.


Abstract

Rising global food prices and the increasing prevalence of food insecurity highlight the imprudence of food waste and the inefficiencies of the current food system. Upcycling food by-products holds significant potential for mitigating food loss and waste within the food supply chain. Food by-products can be utilized to extract nanocellulose, a material that has obtained substantial attention recently due to its renewability, biocompatibility, bioavailability, and a multitude of remarkable properties. Cellulose nanomaterials have been the subject of extensive research and have shown promise across a wide array of applications, including the food industry. Notably, nanocellulose possesses unique attributes such as a surface area, aspect ratio, rheological behavior, water absorption capabilities, crystallinity, surface modification, as well as low possibilities of cytotoxicity and genotoxicity. These qualities make nanocellulose suitable for diverse applications spanning the realms of food production, biomedicine, packaging, and beyond. This review aims to provide an overview of the outcomes and potential applications of cellulose nanomaterials derived from food by-products. Nanocellulose can be produced through both top-down and bottom-up approaches, yielding various types of nanocellulose. Each of these variants possesses distinctive characteristics that have the potential to significantly enhance multiple sectors within the commercial market.

Mushroom Tyrosinase: Six Isoenzymes Catalyzing Distinct Reactions

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“Mushroom tyrosinase” from the common button mushroom is the most frequently used source of tyrosinase activity, both for basic and applied research. Here, the complete tyrosinase family from Agaricus bisporus var. bisporus (abPPO1-6) was cloned from mRNA and expressed heterologously using a single protocol. All six isoenzymes accept a wide range of phenolic and catecholic substrates, but display pronounced differences in their specificity and enzymatic reaction rate. AbPPO3 ignores γ-l-glutaminyl-4-hydroxybenzene (GHB), a natural phenol present in mM concentrations in A. bisporus, while AbPPO4 processes 100 µM GHB at 4-times the rate of the catechol l-DOPA. All six AbPPOs are biochemically distinct enzymes fit for different roles in the fungal life cycle, which challenges the traditional concept of isoenzymes as catalyzing the same chemical reaction and varying only in secondary properties. Transferring this approach to other enzymes and organisms will greatly stimulate both the study of the in vivo function(s) of enzymes and the application of these highly efficient catalysts.

Insight into the d‐p Orbital Hybridization of Ru and B Dispersed g‐C3N4 Catalysts for Nitrogen Reduction Reaction

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Electrochemical nitrogen reduction reaction (NRR) is considered as an important strategy for ammonia using green energy. Single atom catalysts (SACs) with a metal atom as active site have been shown its advantages to high ammonia yield and low energy consumption. In this work, we proposed a new concept of SACs with the capacity of d-p orbital hybridization. These computationally designed SACs contained a metal and non-metal pair anchored on g-C3N4 slab. Among these SACs studied in the present work, RuB@g-C3N4 catalyst performed the best activity for NRR with low onset potential of -0.33 V by a two-step scanning computations using density functional theory (DFT). Moreover, suppressing effectively to the competitive hydrogen evolution reaction (HER) also make it more selective. It was further revealed that the hybridization of p-d orbitals between metal and nonmetal could regulate the electronics of active sites and facilitate the adsorption and charge transfer of adsorbed N2 molecules resulting in enhanced catalytic performance. This work demonstrated an alternative way to further enhance the catalytic activity of SACs by introducing a non-metal atom.

Advanced Functionalized Nanoclusters (Cu, Ag, and Au) as Effective Catalyst for Organic Transformation Reactions

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A considerable amount of research has been carried out in recent years on synthesizing metal nanoclusters (NCs), which have wide applications in the field of optical materials with non-linear properties, bio-sensing, and catalysis. Aside from being structurally accurate, the atomically precise NCs possess well-defined compositions due to significant tailoring, both at the surface and the core, for certain functionalities. To illustrate the importance of atomically precise metal NCs for catalytic processes, this review emphasizes 1) the recent work on Cu, Ag, and Au NCs with their synthesis, 2) the parameters affecting the activity and selectivity of NCs catalysis, and 3) the discussion on the catalytic potential of these metal NCs. Additionally, metal NCs will facilitate the design of extremely active and selective catalysts for significant reactions by elucidating catalytic mechanisms at the atomic and molecular levels. Future advancements in the science of catalysis are expected to come from the potential to design NCs catalysts at the atomic level.