A TBPB-Mediated C-3 Cycloalkylation and Formamidation of 4-Arylcoumarin
作者:Sarangthem Joychandra Singh、Bilal Ahmad Mir、Bhisma K. Patel
DOI:10.1002/ejoc.201701677
日期:2018.2.28
A Tert‐butyl Peroxybenzoate (TBPB) mediated cycloalkylation and formamidation efficiently took place at 120°C in chlorobenzene or the corresponding formamide, respectively. The cycloalkylation required the addition of aceticacid, whereas the formamidation proceeded in its absence. This radical‐mediated process tolerated a broad scope of substrates and provided the products in moderate to good yields
A straightforward and atom-economical base-free palladium-catalyzed regioselective direct arylation of coumarins and chromenones is devised. This protocol is compatible with a wide variety of electron-donating and -withdrawing substituents and allows construction of various biologically important flavone and neoflavone backbones.
Microwave-Promoted, One-Pot, Solvent-Free Synthesis of 4-Arylcoumarins from 2-Hydroxybenzophenones
作者:José Crecente-Campo、M. Pilar Vázquez-Tato、Julio A. Seijas
DOI:10.1002/ejoc.201000051
日期:2010.7
4-Arylcoumarins are synthesized in very good yields through solvent-free microwave irradiation of 2-hydroxybenzophenones and alkyl malonate in the presence of DBU. The one-pot synthesis is carried out with Knoevenagel condensation, intramolecular lactonization, and decarboxylation reactions. The method can be applied to a broad scope of neoflavonoids.