Homolytic Reduction of Onium Salts

Onium salts have proved to be efficient sources of carbon-centered radicals. They can undergo homolytic reduction by single electron transfer (SET) and participate in subsequent synthetic transformations. This review aims to provide an overview on the behavior of onium salts including diazonium, sulfonium, selenonium, telluronium, phosphonium and iodonium cations toward various reductive methods such as radiolysis, electrolysis, photolysis or the use of SET reagents. Mechanistic and synthetic aspects are presented. Applications in polymers and materials science are not covered

Evolution of Triangular All-Metal Aromatic Complexes from Bonding Quandaries to Powerful Catalytic Platforms

This manuscript describes an overview on the literature detailing the observation of trinuclear complexes that present delocalized metal–metal bonds similar to those of regular aromatics, which are formed combining main group elements. A particular emphasis is given to the structural and electronic features of aromatic clusters that are sufficiently stable to allow their isolation. In parallel to the description of their key bonding properties, the work presents reported catalytic applications of these complexes, which already span from elaborated C–C-forming cascades to highly efficient cross-coupling methods. These examples present peculiar aspects of the unique reactivity exerted by all-metal aromatic complexes, which can often be superior to their established, popular mononuclear peers in terms of chemoselectivity and chemical robustnes

Oxidation of bis-sulfinyl carbanions as the pivot of ionic/radical tandem reactions

International audience[1,4]-additions of various nucleophiles such as lithiated carbamates, alkoxides or ester enolates onto enantiopure alkylidene bis-sulfoxides proceed with high diastereoselectivity. The oxidation of the resulting carbanions with iron(III) salts induces the radical cyclizations onto alkenes with a high diastereoselectivity leading to enantiopure carbo- or heterocycles. Moreover, allylic radicals have been generated by deprotonation or [1,6]-conjugate addition from alkylidene bis-sulfoxides followed by oxidation

Synthesis of marmycin A and investigation into its cellular activity

Anthracyclines such as doxorubicin are used extensively in the treatment of cancers. Anthraquinone-related angucyclines also exhibit antiproliferative properties and have been proposed to operate via similar mechanisms, including direct genome targeting. Here, we report the chemical synthesis of marmycin A and the study of its cellular activity. The aromatic core was constructed by means of a one-pot multistep reaction comprising a regioselective Diels-Alder cycloaddition, and the complex sugar backbone was introduced through a copper-catalysed Ullmann cross-coupling, followed by a challenging Friedel-Crafts cyclization. Remarkably, fluorescence microscopy revealed that marmycin A does not target the nucleus but instead accumulates in lysosomes, thereby promoting cell death independently of genome targeting. Furthermore, a synthetic dimer of marmycin A and the lysosome-targeting agent artesunate exhibited a synergistic activity against the invasive MDA-MB-231 cancer cell line. These findings shed light on the elusive pathways through which anthraquinone derivatives act in cells, pointing towards unanticipated biological and therapeutic applications

Nouvelles réactivités d'hétéroéléments (beta-Elimination de radicaux phosphores réactivité des sulfinamides et sulfonimidamides vis-à-vis de l'iodosobenzene)

PARIS-BIUSJ-Thèses (751052125) / SudocPARIS-BIUSJ-Physique recherche (751052113) / SudocSudocFranceF