RESUMO
Highly functionalized indoles and indolones were prepared via selectivity-switchable mono- or diolefinations. The Julia olefination of the products followed by a Brønsted acid-prompted cyclization afforded indolones, whereas the indoles were obtained by a sequential Wittig olefination and electrocyclization. This method opens divergent access to highly functionalized nitrogen-containing bicyclic or tricyclic heterocycles.
RESUMO
The direct dehydrogenative C-H cleaving carbonylative lactamization of 2-arylanilines promoted by visible light and potassium bases is reported. Solvent DMF acts as the sole carbonyl source in the absence of an oxidant. The irreversible release of hydrogen gas drags this reaction to the stable phenanthridinone products. This work provides a direct conversion of a broad range of 2-arylanilines to various phenanthridinones. This method could be applied in the synthesis of bioactive molecules and organic optoelectronic materials.
RESUMO
We report a simple and efficient visible-light-induced transition-metal-free hydrogenation of aryl halides. The combined visible light and base system is used to initiate the desired radical-mediated hydrogenation. A variety of aryl fluorides, chlorides, bromides, and iodides could be reduced to the corresponding (hetero)arenes with excellent yields under mild conditions. Various functional groups and other heterocyclic compounds are tolerated.
RESUMO
A heterogeneous iridium-complex-catalyzed N-O-cleaving rearrangement/cyclization of 2,3-dihydroisoxazoles with alkenes has been developed. It provides divergent access to multiple substituted pyrrolidines, pyrroles, and carbazoles. The iridium catalyst remains highly catalytic active after seven cycles. The gram-scale synthesis afforded a carbazole with strong bluish-violet fluorescence.