Isoindolones and related N-heterocycles via palladium nanoparticle-catalyzed 3-component cascade reactions.

Abstract

Non-phosphine-containing cyclopalladated N-heterocycles possessing either sp2 C-Pd(II) or sp3 C-Pd(II) bonds and simple Pd(II) salts are precursors of Pd(0) nanoparticles whose initial morphology is dependent on the nature of the precursor. Addition of polyvinylpyrrolidone (pvp) dramatically increases catalyst lifetime. Nanoparticle generation can be achieved at ambient temperature in the presence of carbon monoxide by a process akin to the water-gas shift reaction. Allene also lowers the temperature required for nanoparticle generation. 3-Component catalytic cascades employing one or both of these substrates provide access to a variety of 5- and 6-membered N-heterocycles including isoindolones, N-aminoisoindolones, phthalazones, dihydroisoquinolines, and isoquinolones.