Samarium(II)-mediated spirocyclization by intramolecularaddition of arylradicals onto an aromatic ring was achieved by the reaction of N-(2-iodophenyl)-N-alkylbenzamides with SmI2 in the presence of HMPA, yielding spirocyclic indolin-2-one derivatives. The ether congeners afford spirocyclic benzofuran derivatives in moderate yields by arylradicaladdition onto a benzene ring without having an electron-withdrawing
A palladium-catalyzed multicomponentreaction (MCR) involving aryne, CO, and aniline is established for straightforward assembly of a phenanthridinone scaffold through C–H bond activation. Free combination with multiple kinds of readily available anilines and arynes is facilely achieved for phenanthridinone construction without prefunctionalization. Representative natural products were subsequently
Diels-Alderreactions of 3-nitro-2(1H)-quinolones with 1,3-butadiene derivatives were carried out to give the phenanthridone derivatives under both atmospheric and high pressure conditions. Furthermore, the reactivity of 3-substituted 2(1H)-quinolones acting as a dienophile with 2,3-dimethyl-1,3-butadiene was examined using molecular orbital (MO) calculation.
Palladium-catalyzed cyclization of benzamides with arynes: application to the synthesis of phenaglydon and N-methylcrinasiadine
作者:Sandeep Pimparkar、Masilamani Jeganmohan
DOI:10.1039/c4cc05252h
日期:——
N-Methyl or methoxy substituted benzamides reacted with benzynes in the presence of a palladium catalyst, yielding tricyclic N-methyl or N-methoxy substituted phenanthridinones.
A direct and efficient strategy for the synthesis of phenanthridinone from the coupling of N-methyl benzamide and aryl boronic acid via C–C/C–N bond formation catalyzed by a newly synthesized dinuclear palladium(II) complex has been reported. The unprecedented formation of the dinuclear palladium(II) hydrazone complex was fully characterized, and the molecular structure of the complex was studied by