Synthesis of Quinolines, 2-Quinolones, Phenanthridines, and 6(5H)-Phenanthridinones via Palladium[0]-Mediated Ullmann Cross-Coupling of 1-Bromo-2-nitroarenes with β-Halo-enals, -enones, or -esters
摘要:
Palladium[0]-mediated Ullmann cross-coupling of 1-bromo-2-nitrobenzene (1 R = H) and its derivatives with a range of beta-halo-enals, -enones, or -esters readily affords the corresponding beta-aryl derivatives, which are converted into the corresponding quinolines, 2-quinolones, phenanthridines, or 6(5H)-phenanthridinones on reaction with dihydrogen in the presence of Pd on C or with TiCl3 in aqueous acetone.
Visible-Light-Promoted and One-Pot Synthesis of Phenanthridines and Quinolines from Aldehydes and <i>O</i>-Acyl Hydroxylamine
作者:Xiao-De An、Shouyun Yu
DOI:10.1021/acs.orglett.5b01096
日期:2015.6.5
A one-pot synthesis of phenanthridines and quinolines from commercially available or easily prepared aldehydes has been reported. O-(4-Cyanobenzoyl)hydroxylamine was utilized as the nitrogen source to generate O-acyl oximes in situ with aldehydes catalyzed by Bronsted acid. O-Acyl oximes were then subjected to visible light photoredox catalyzed cyclization via iminyl radicals to furnish aza-arenes. A variety of phenanthridines and quinolines have been prepared assisted by Bronsted acid and photocatalyst under visible light at room temperature with satisfactory yields.