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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]

Abstract: This short review describes our work on the development of dendrimeric antagonists of DC-SIGN, a dendritic cells (DCs) receptor recognizing highly mannosylated structures and primarily involved in the recognition [...]

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]

Herein, we report our study on the design and development of a novel photocarboxylation method. We have used an organic photoredox catalyst (PC, 4CzIPN) and differently substituted dihydropyridines (DHPs) in combination with an organic base (1,5,7-triazabicyclodec-5-ene, TBD) to access a proton-coupled electron transfer (PCET) based manifold. In depth mechanistic investigations merging experimental analysis (NMR, IR, cyclic voltammetry) and density-functional theory (DFT) calculations reveal the key activity of a H-bonding complex between the DHP and the base. The thermodynamic and kinetic benefits of the PCET mechanism allowed the implementation of a redox-neutral fixation process leading to synthetically relevant carboxylic acids (18 examples with isolated yields up to 75%) under very mild reaction conditions. Finally, diverse product manipulations were performed to demonstrate the synthetic versatility of the obtained products.

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., (© 2022 Wiley-VCH GmbH.)

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., (© 2020 Wiley-VCH GmbH.)

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., (© 2018 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA.)

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., (© 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)