Reactivity of the 2-aryl-6,8-dibromo-2,3-dihydroquinolin-4(1H)-ones in apalladium catalyzed Sonogashira cross-coupling reaction

Abstract

Pd/C-PPh3{CuI catalyzed Sonogashira cross-coupling of the 2-aryl-6,8-dibromo-2,3-dihydroquinolin-4(1H)-ones with phenyl acetylene or 3-butyn-1-ol afforded the corresponding 8-alkynylated quinolin-4(1H)-one derivatives,exclusively. Double carbo-substitution to afford the 6,8-dialkynyl derivatives was observed when PdCl2(PPh3)2wasused as Pd(0) source. The monoalkynylated derivatives were, in turn, subjected to PdCl2in acetonitrile under re ux toafford either the corresponding 2,4-diaryl-8-bromopyrrolo[3,2,1-ij]quinolinones or the 8-(4-hydroxybutanoyl)-substitutedquinolinone derivatives, exclusively. Suzuki{Miyaura cross-coupling of the 2-aryl-6-bromo-8-(alkynyl)quinolin-4-onesafforded the 2,4,8-trisubstituted pyrrolo[3,2,1-ij]quinolin-6-ones.