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The integration of photovoltaic technologies within agricultural settings, also known as agrivoltaics, is attracting increasing attention as a sustainable approach to ensure both clean energy and food supply. The success of this strategy relies on the development of innovative materials that can selectively convert specific wavelengths into energy while being transparent to photosynthetically relevant light. To this aim, here we report our endeavors in the synthesis of a new class of D‐π‐A‐π‐D quinoxaline fluorophores and their use in the preparation of wavelength‐selective luminescent solar concentrators. The dyes were expeditiously prepared following a direct arylation protocol and extensively characterized by spectroscopic analyses and computational studies. They present high light harvesting ability in the green region of the visible spectrum and good emission properties, which were fully retained in the solid state when embedded into a poly methyl methacrylate (PMMA) matrix. These materials were employed to construct LSC devices of promising efficiency, fostering further developments for the use of wavelength‐selective LSC in agrivoltaic systems. [ABSTRACT FROM AUTHOR]

Here, we report a general approach to the synthesis of the difluoroalkyl bicycloalkanes (CF2‐BCAs), as structural surrogates of aryl ketones and ethers. The chemistry is driven by a dihydrobenzoacridine photocatalyst, that engages in a catalytic electron‐donor acceptor (EDA) complex, or directly reduces the fluorinated substrate. These two convergent manifolds lead to the generation of the R‐CF2 radical, that reacts with the [1.1.1]‐ or [3.1.1.]‐propellane. The method is extremely general, and extendable to complex bioactive molecules (30 examples, up to 87 % yield). The structural features of the CF2‐BCP hybrid bioisostere were investigated by single crystal X‐ray. Finally, we synthesised a CF2‐BCP analogue of a Leukotriene A4 hydrolase inhibitor, replacing the original aryl ether motif. In silico docking studies indicated that this new analogue maintains the same arrangement within the enzyme pocket, profiling the use of the CF2‐BCA hybrid bioisostere in medicinal chemistry settings. [ABSTRACT FROM AUTHOR]

The synthesis of four membered heterocycles usually requires multi‐step procedures and prefunctionalized reactants. A straightforward alternative is the photochemical [2+2]‐heterocycloaddition between an alkene and a carbonyl derivative, conventionally based on the photoexcitation of this latter. However, this approach is limited by the absorption profile of the carbonyl, requiring in most of the cases the use of high‐energy UV‐light, that often results in undesired side reactions and/or the degradation of the reaction components. The development of new and milder visible light‐driven [2+2]‐heterocycloadditions is, therefore, highly desirable. In this Review, we highlight the most relevant achievements in the development of [2+2]‐heterocycloadditions promoted by visible light, with a particular emphasis on the involved reaction mechanisms. The open challenges will also be discussed, suggesting new possible evolutions, and stimulating new methodological developments in the field. [ABSTRACT FROM AUTHOR]

Multivalent ligands of the C‐type lectin receptor DC‐SIGN have emerged as effective antiadhesive agents against various pathogens. Some years ago, we described a hexavalent DC‐SIGN ligand, Polyman‐26, designed to bridge two of the four binding sites displayed by the receptor. In this work, we present our efforts to accomplish simultaneous coordination of all four carbohydrate binding sites of DC‐SIGN through the synthesis of cross‐shaped glycodendrimers. The tailored rigid scaffold allowed multivalent presentation of glycomimetics in a spatially defined fashion, while providing good water solubility to the constructs. Evaluation of the biological activity by SPR assays revealed strong binding avidity towards DC‐SIGN and increased selectivity over langerin. Inhibition of DC‐SIGN binding to SARS‐CoV‐2 spike protein and of DC‐SIGN mediated Ebola virus trans‐infection testifies for the glycodendrimers potential application in infection diseases. The tetravalent platform described here is easily accessible and can be used in modular fashion with different ligands, thus lending itself to multiple applications. [ABSTRACT FROM AUTHOR]

The article titled "Front Cover: Green Light-Responsive D-A-D Quinoxaline Emitters for Luminescent Solar Concentrators: Potential Integration in Agrivoltaic Systems" discusses the use of polymeric films doped with quinoxaline-based emitters for luminescent solar concentrators. These materials selectively absorb green light, which is non-productive for plant photosynthesis, making them suitable for integrating photovoltaic technologies in agricultural settings. The authors suggest that this approach can provide both clean energy and food simultaneously. The article is authored by Giulio Goti, Gianna Reginato, Carmen Coppola, Alessio Dessì, Daniele Franchi, Alessandro Mordini, Alberto Picchi, Andrea Pucci, Adalgisa Sinicropi, Lorenzo Zani, and Massimo Calamante. [Extracted from the article]

Organic Near‐Infrared luminophores have found broad application as functional materials, but the development of efficient NIR emitters is still a challenging goal. Here we report on a new class of thieno[3,4‐b]pyrazine‐based NIR emitting materials with Aggregation Induced Emission (AIE) properties. The dyes feature a donor–acceptor–donor (D−A−D) structure, with a thienopyrazine acceptor core connected to two triarylamine donor groups bearing a tetraphenylethylene (TPE) moiety. Fast and efficient synthesis allowed the modular preparation of three dyes of tunable absorption and emission profiles. These constructs were extensively characterized by spectroscopic studies in different solvents, which revealed intense light‐harvesting ability and emissions in the deep‐red and NIR region with large Stokes shift values. Remarkably, the dyes exhibited AIE properties, retaining emissive ability in the aggregate state, thus emerging as attractive materials for their potential application in the development of luminescent devices.Novel NIR‐emitting organic dyes with aggregation‐induced emission (AIE) properties are described. The thienopyrazine‐based donor‐acceptor‐donor structure allows for easy tuning of the photophysical properties. The intense light absorption ability and the emission in the red/NIR region, both in solution and in the aggregate phase, make them attractive for potential use as functional organic materials in the development of luminescent devices. [ABSTRACT FROM AUTHOR]

Due to their interactions with C‐type lectin receptors (CLRs), glycans from the helminth Schistosoma mansoni represent promising leads for treatment of autoimmune diseases, allergies or cancer. We chemo‐enzymatically synthesized nine O‐glycans based on the two predominant O‐glycan cores observed in the infectious stages of schistosomiasis, the mucin core 2 and the S. mansoni core. The O‐glycans were fucosylated next to a selection of N‐glycans directly on a microarray slide using a recombinant fucosyltransferase and GDP‐fucose or GDP‐6‐azidofucose as donor. Binding assays with fluorescently labelled human CLRs DC‐SIGN, DC‐SIGNR and MGL revealed the novel O‐glycan O8 as the best ligand for MGL from our panel. Significant binding to DC‐SIGN was also found for azido‐fucosylated glycans. Contrasting binding specificities were observed between the monovalent carbohydrate recognition domain (CRD) and the tetravalent extracellular domain (ECD) of DC‐SIGNR. [ABSTRACT FROM AUTHOR]

Reported herein is a visible‐light‐mediated radical approach to the α‐alkylation of ketones. This method exploits the ability of a nucleophilic organocatalyst to generate radicals upon SN2‐based activation of alkyl halides and blue light irradiation. The resulting open‐shell intermediates are then intercepted by weakly nucleophilic silyl enol ethers, which would be unable to directly attack the alkyl halides through a traditional two‐electron path. The mild reaction conditions allowed functionalization of the α position of ketones with functional groups that are not compatible with classical anionic strategies. In addition, the redox‐neutral nature of this process makes it compatible with a cinchona‐based primary amine catalyst, which was used to develop a rare example of enantioselective organocatalytic radical α‐alkylation of ketones. [ABSTRACT FROM AUTHOR]

We report a visible‐light‐mediated organocatalytic strategy for the enantioselective acyl radical conjugate addition to enals, leading to valuable 1,4‐dicarbonyl compounds. The process capitalizes upon the excited‐state reactivity of 4‐acyl‐1,4‐dihydropyridines that, upon visible‐light absorption, can trigger the generation of acyl radicals. By means of a chiral amine catalyst, iminium ion activation of enals ensures a stereoselective radical trap. We also demonstrate how the combination of this acylation process with a second catalyst‐controlled bond‐forming event allows to selectively access the full matrix of all possible stereoisomers of the resulting 2,3‐substituted 1,4‐dicarbonyl products. [ABSTRACT FROM AUTHOR]

Corrigendum: Mechanisms and Synthetic Strategies in Visible Light-Driven [2+2]-Heterocycloadditions In order to better represent the work of the Schindler and Sivaguru groups a sentence on page 13 of this Review article should be modified as shown below. "Their strategy relied on the selective activation of the alkene functionality within the oxime substrate B 80 b , while avoiding the excitation of the imine moiety." should be corrected to "As previously demonstrated by Sivaguru and co-workers SP 57i sp for UV-light PB reactions, it was possible to rely on the selective activation of the alkene functionality within the oxime substrate B 80 b , while avoiding the excitation of the imine moiety". [Extracted from the article]

In order to better represent the work of the Schindler and Sivaguru groups a sentence on page 13 of this Review article should be modified as shown below. "Their strategy relied on the selective activation of the alkene functionality within the oxime substrate B 80 b , while avoiding the excitation of the imine moiety." should be corrected to "As previously demonstrated by Sivaguru and co-workers SP 57i sp for UV-light PB reactions, it was possible to rely on the selective activation of the alkene functionality within the oxime substrate B 80 b , while avoiding the excitation of the imine moiety". [Extracted from the article]

Hsp90 is a molecular chaperone that plays a pivotal role in the cell life cycle. ATP-regulated internal dynamics are critical to Hsp90 function and we recently demonstrated that these dynamics can be modulated in an allosteric fashion; the protein C-terminal domain (CTD) can be effectively targeted with a family of 2-phenyl-benzofuran derivatives. Here we describe the expansion of the initial library, reporting 28 new derivatives that explore the chemical space at opposite ends of the benzofuran scaffold. Interactions of the compounds with a full-length protein homolog were explored by Saturation Transfer Difference (STD) NMR spectroscopy. In this context we also report the interaction epitope of Novobiocin, a known CTD inhibitor. [ABSTRACT FROM AUTHOR]

Antagonists of mannose binding lectin (MBL) have shown a protective role against brain reperfusion damage after acute ischemic stroke. Here we describe the design and streamlined synthesis of glycomimetic MBL antagonists based on a new tetravalent dendron scaffold. The dendron was developed by optimisation of a known polyester structure previously demonstrated to be very efficient for ligand presentation to MBL. Replacement of a labile succinyl ester bond with a more robust amide functionality, use of a longer and more hydrophilic linker, fast modular synthesis and orthogonal functionalisation at the focal point are the main features of the new scaffold. The glycoconjugate constructs become stable to silica gel chromatography and to water solutions at physiological pH, while preserving water solubility and activity in an SPR assay against the murine MBL-C isoform. Higher-order constructs were easily assembled, as demonstrated by the synthesis of a 16-valent dendrimer, which leads to two orders of magnitude increase in activity over the tetravalent version against MBL-C. [ABSTRACT FROM AUTHOR]

Keywords: Carbohydrates; DC-SIGN; Dendrimers; Glycomimetics; Langerin EN Carbohydrates DC-SIGN Dendrimers Glycomimetics Langerin 1 1 1 08/09/22 20220805 NES 220805 B The Front Cover b shows a blueprint for the design of a multivalent ligand of the C-type lectin receptor DC-SIGN. This molecular architecture achieves strong binding avidity towards DC-SIGN and increased selectivity over the C-type lectin langerin, which is characterized by a distinct spatial arrangement of the carbohydrate recognition domains. Carbohydrates, DC-SIGN, Dendrimers, Glycomimetics, Langerin. [Extracted from the article]