We report herein a simple, additive- and metal-free, photoinduced, dual C–H/C–X-borylation of chloro-, bromo-, and iodoarenes. The reaction produces 1,2- and 1,3-diborylarenes on gram scales under batch and continuous flow conditions. The regioselectivity of the dual C–H/C–X-borylation is determined by the solvent and the substituents in the parent haloarenes.
We report herein that symmetrical and non-symmetrical N-heterobiaryls are produced by a potassium tert-butoxide-mediated dimerization of heterocyclic N-oxides. The reaction is scalable and transition metal-free, and can be carried out under thermal and microwave conditions. Preliminary mechanistic studies point to the involvement of radical anionic intermediates arising from the N-oxide substrates and potassium tert-butoxide.
Perylene diimide derivatives have attracted initial interest as industrial dyes. Recently, much attention has been focused on their strong π–π stacks resulting from the large PDI aromatic core. These PDI stacks have distinct optical properties, and provide informative models that could mimic light-harvesting systems and initial charge transfer typical of photosynthetic systems. The absorption property of PDI derivatives may be tuned from visible to near-infrared region by peripheral substitution. We have studied a new class of PDI derivatives with aryl substituents derived from the side chains of aromatic aminoacids (Tyrosine, Tryptophan and Phenylalanine). We have investigated their absorption and the fluorescence properties in a set of organic solvents and established their different tendencies to aggregate in solution despite their solubility. Most aggregation appears to be unordered. One PDI analogue (the one formed from Tyr) in Methanol, however, appears to form J-type aggregates. Based on our results the compounds appear to be promising for future investigations regarding the interaction of these dyes with biomolecules.
Few nucleoside-derived natural products have been identified from animals, despite the ubiquity of nucleosides in living organisms. Here, we use a combination of synthesis and the emerging electron microscopy technique microcrystal electron diffraction to determine the structures of several N 3 -(β-glucopyranosyl)uric acid derivatives in Caenorhabditis elegans. These noncanonical gluconucleosides further integrate an ascaroside moiety, for which we present a shortened synthetic route. The production of a phosphorylated gluconucleoside is influenced by evolutionarily conserved insulin signaling.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.