No abstract

The transformation of light into chemical energy is a leitmotiv in the development of sustainable and environmentally concerned chemical processes. Chemists invented original concepts to address this purpose, like photoredox catalysis, which became a wonderful tool to transform simple organic compounds into high‐value products. Nevertheless, the most relevant transition metal based photocatalysts suffer from major disadvantages like toxicity, cost, and poor recyclability potential. To circumvent this, we propose a new generation of heterogeneous photoredox catalysts resulting from the combination of porous silica materials and Rose Bengal. They promote carbon–carbon bond formations under visible‐light in environmentally benign solvent using air as the only stoichiometric redox partner. The pure covalent photocatalytic system provides a robust and recyclable system for greener catalysis. This report would be of broad significance because it addresses important sustainability issues: recycling, non‐toxic metal‐free photocatalysts, and less‐waste‐producing chemical process.

Direct metal-free Near Infra-Red photoredox catalysis is applied to organic oxidation, photosensitization and reduction, involving cyanines sas photocatalysts. This photocatalyst is competitive with conventional reactions catalyzed under visible light. Kinetic...

Near-Infrared photoredox catalysis is now consider as the next evolution of this field.

Trialkylaluminum compounds perform a diastereoselective 1,6-ring fragmentation of alkenylcyclopropane. This new tool allows the preparation of hydrocarbon compounds containing two distant stereocenters with a good diastereocontrol. Inspired by the biosynthesis of botryococcene this methodology was applied successfully to the diastereo- and enantioselective preparation of this triterpene and its epimer.

Herein, unprecedented uses of squaraines derivatives as new organic near-infrared photocatalysts are reported. These efficient molecular tools are able to promote oxidation and reduction for organic transformations through photocatalytic conditions....

Heterogenization of the photocatalyst appears to be a valuable solution to reach sustainable processes. Rapid and efficient synthesis of supported photocatalyst is still a remaining challenge and the choice of the support material is crucial. The present study aims at preparing a new generation of hybrid inorganic/organic photocatalysts based on silica mesoporous material and Eosin Y. These results highlight the influence of non-covalent interactions between the material support and the reagent impacting the selectivity of the reaction.

The domino anionic fragmentation of 2-nitrophenyl-1,3-cyclohexanediones containing an electrophilic appendage such as aldehyde and epoxide is disclosed. This reaction, initiated by a series of nucleophiles, involves the generation of an intermediate hydroxylate followed by the regioselective formation and fragmentation of an intermediate lactolate into enolate. This strategy, devoid of any protecting group, enlarges the initial ring and provides an original access to decorated 9-membered lactones with a fused indole unit.