Isocyanate-based multicomponent reactions.

Since their discovery, multicomponent reactions have attracted significant attention due to their versatility and efficiency. This review aims to explore the latest advancements in isocyanate-based multicomponent reactions and the sophisticated chemical opportunities they present for generating molecules of interest. The added value of the methodologies described, supported by mechanism schemes, as well as scopes of application, will be discussed.

Platform for Multiple Isotope Labeling via Carbon-Sulfur Bond Exchange.

In this work, we explore a nickel-catalyzed reversible carbon-sulfur (C-S) bond activation strategy to achieve selective sulfur isotope exchange. Isotopes are at the foundation of applications in life science, such as nuclear imaging, and are essential tools for the determination of pharmacokinetic and dynamic profiles of new pharmaceuticals. However, the insertion of an isotope into an organic molecule remains challenging, and current technologies are element-specific.

Environmental and Health Impacts of Graphene and Other Two-Dimensional Materials: A Graphene Flagship Perspective.

Two-dimensional (2D) materials have attracted tremendous interest ever since the isolation of atomically thin sheets of graphene in 2004 due to the specific and versatile properties of these materials. However, the increasing production and use of 2D materials necessitate a thorough evaluation of the potential impact on human health and the environment. Furthermore, harmonized test protocols are needed with which to assess the safety of 2D materials.

One-year post-exposure assessment of C-few-layer graphene biodistribution in mice: single repeated intratracheal administration.

Research on graphene-based nanomaterials has experienced exponential growth in the last few decades, driven by their unique properties and their future potential impact on our everyday life. With the increasing production and commercialization of these materials, there is significant interest in understanding their fate . Herein, we investigated the distribution of C-few-layer graphene (C-FLG) flakes (lat.

Exploration of the Copper-Catalyzed Sydnone and Sydnonimine-Alkyne Cycloaddition Reactions by High-Throughput Experimentation.

The reactivity of sydnones and sydnonimines toward terminal alkynes under copper catalysis has been explored using High-Throughput-Experimentation. A large panel of ligands and reaction conditions have been tested to optimize the copper-catalyzed sydnone click reaction discovered by our group ten years ago. This screening approach led to the identification of new ligands, which boosted the catalytic properties of copper and allowed the discovery of a new copper-catalyzed click-and-release reaction involving sydnonimines.

Correlative radioimaging and mass spectrometry imaging: a powerful combination to study C-graphene oxide biodistribution.

Research on graphene based nanomaterials has flourished in the last decade due their unique properties and emerging socio-economic impact. In the context of their potential exploitation for biomedical applications, there is a growing need for the development of more efficient imaging techniques to track the fate of these materials. Herein we propose the first correlative imaging approach based on the combination of radioimaging and mass spectrometry imaging for the detection of Graphene Oxide (GO) labelled with carbon-14 in mice.

Catalytic methoxylation of aryl halides using C- and C-labeled CO.

The functionalization of carbon dioxide (CO) into high-value building blocks is a relevant topic in carbon isotope labeling, where CO is the primary carbon source. A catalytic methoxylation of aryl halides directly from [C] and [C]CO is reported. Relying on the intermediacy of the methoxyborane BBN-OCH, as a new secondary nucleophilic labeled source, this strategy allowed labeling of a series of substrates, including challenging pharmaceuticals containing tertiary alkyl amine substituents.

Detection of expanded-spectrum cephalosporin hydrolysis by lateral flow immunoassay.

Early detection of expanded-spectrum cephalosporin (ESC) resistance is essential not only for an effective therapy but also for the prompt implementation of infection control measures to prevent dissemination in the hospital. We have developed and validated a lateral flow immunoassay (LFIA), called LFIA-CTX test, for the detection of ESC (cefotaxime) hydrolytic activity based on structural discrimination between the intact antibiotic and its hydrolysed product. A single bacterial colony was suspended in an extraction buffer containing cefotaxime.

A general procedure for carbon isotope labeling of linear urea derivatives with carbon dioxide.

Carbon isotope labeling is a traceless technology, which allows tracking the fate of organic compounds either in the environment or in living organisms. This article reports on a general approach to label urea derivatives with all carbon isotopes, including 14C and 11C, based on a Staudinger aza-Wittig sequence. It provides access to all aliphatic/aromatic urea combinations.

Direct Carbon Isotope Exchange of Pharmaceuticals via Reversible Decyanation.

The incorporation of carbon-14 allows tracking of organic molecules and provides vital knowledge on their fate. This information is critical in pharmaceutical development, crop science, and human food safety evaluation. Herein, a transition-metal-catalyzed procedure enabling carbon isotope exchange on aromatic nitriles is described.

Click and Release Chemistry for Activity-Based Purification of β-Lactam Targets.

β-Lactams, the cornerstone of antibiotherapy, inhibit multiple and partially redundant targets referred to as transpeptidases or penicillin-binding proteins. These enzymes catalyze the essential cross-linking step of the polymerization of cell wall peptidoglycan. The understanding of the mechanisms of action of β-lactams and of resistance to these drugs requires the development of reliable methods to characterize their targets.

Carbon isotope labeling of carbamates by late-stage [C], [C] and [C]carbon dioxide incorporation.

A general procedure for the late-stage [11C], [13C] and [14C]carbon isotope labeling of cyclic carbamates is reported. This protocol allows the incorporation of carbon dioxide, the primary source of carbon-14 and carbon-11 radioisotopes, in a direct, cost-effective and sustainable manner. A disconnection/reconnection strategy, involving ring opening/isotopic closure, was also implemented.

Development of a Mass Spectrometry Imaging Method for Detecting and Mapping Graphene Oxide Nanoparticles in Rodent Tissues.

Graphene-based nanoparticles are continuously being developed for biomedical applications, and their use raises concerns about their environmental and biological impact. In the literature, some imaging techniques based on fluorescence and radioimaging have been used to explore their fate . Here, we report on the use of label-free mass spectrometry and mass spectrometry imaging (MSI) for graphene oxide (GO) and reduced graphene oxide (rGO) analyses in rodent tissues.

Sydnone-based turn-on fluorogenic probes for no-wash protein labeling and in-cell imaging.

We report the synthesis and use of sydnone-based profluorophores as tools for imaging applications. These new probes display exquisite reactivity towards strain promoted cycloaddition reactions with cycloalkynes allowing fast, efficient and selective labeling in biological media. Styryl-pyridinium sydnone probes were found particularly interesting for click reactions to proceed selectively inside cells.

Sydnone-coumarins as clickable turn-on fluorescent sensors for molecular imaging.

Copper-catalyzed and copper-free sydnone-alkyne cycloaddition reactions have emerged as complementary click tools for chemical biology but their use in bioorthogonal labeling is still in its infancy. Herein, combinations of alkynes and coumarin-sydnones were screened for their ability to generate pyrazole products displaying strong fluoroscence enhancement compared to reactants. One sydnone was identified as a particularly suitable new turn-on probe for protein labeling.

Bioorthogonal Click and Release Reaction of Iminosydnones with Cycloalkynes.

We report the discovery of a new bioorthogonal click-and-release reaction involving iminosydnones and strained alkynes. This transformation leads to two products resulting from the ligation and fragmentation of iminosydnones under physiological conditions. Optimized iminosydnones were successfully used to design innovative cleavable linkers for protein modification, thus opening up new areas in the fields of drug release and target-fishing applications.

Organometallic nucleoside analogues with ferrocenyl linker groups: synthesis and cancer cell line studies.

Examples of organometallic compounds as nucleoside analogues are rare within the field of medicinal bioorganometallic chemistry. We report on the synthesis and properties of two chiral ferrocene derivatives containing a nucleobase and a hydroxyalkyl group. These so-called ferronucleosides show promising anticancer activity, with cytostatic studies on five different cancer cell lines indicating that both functional groups are required for optimal activity.

A ferrocene nucleic acid oligomer as an organometallic structural mimic of DNA.

The design, synthesis and electrochemical behaviour of an oligomer consisting of linked thymine-functionalised ferrocene units are reported, which, as a so-called form of ferrocene nucleic acid (FcNA), acts as a structural mimic of DNA.