An Unusual Chemoselective Hydrogenation of Quinoline Compounds Using Supported Gold Catalysts

Citations Over TimeTop 10% of 2012 papers

Abstract

The pursuit of modern sustainable chemistry has stimulated the development of innovative catalytic processes that enable chemical transformations to be performed under mild and clean conditions with high efficiency. Herein, we report that gold nanoparticles supported on TiO(2) catalyze the chemoselective hydrogenation of functionalized quinolines with H(2) under mild reaction conditions. Our results point toward an unexpected role for quinolines in gold-mediated hydrogenation reactions, namely that of promoter; this is in stark contrast to what prevails in the traditional noble metal Pd-, Pt-, and Ru-based catalyst systems, in which quinolines and their derivatives typically act as poisons. As a result of the remarkable promotional effect of quinoline molecules to H(2) activation over supported gold, the transformation can proceed smoothly under very mild conditions (even at temperatures as low as 25 °C). Of practical significance is that various synthetically useful functional groups including halogens, ketone, and olefin remain intact during the hydrogenation of quinolines. Moreover, the protocol also shows promise for the regiospecific hydrogenation of the heterocyclic ring of a variety of other biologically important heteroaromatic nitrogen compounds, such as isoquinoline, acridine, and 7,8-benzoquinoline, in a facile manner. Apart from its importance in catalytic hydrogenation, we believe that this intriguing self-promoted effect by reactant molecules may have fundamental implications for the broad field of gold catalysis and form the basis for development of new catalytic procedures for other key transformations.

Related Papers

• → Efficient synthesis of pyrrolo[2,1‐a]isoquinoline and pyrrolo[1,2‐a]quinoline derivatives in aqueous media(2009)26 cited
• → Studies on quinoline and isoquinoline derivatives. IV. Reaction of quinoline and isoquinoline N-oxides with 3-aminocrotononitrile and related compounds.(1979)5 cited
• → Polyhalogenoheterocyclic compounds. Part 37 [1]. Perfluorotetrahydro-quinoline, -isoquinoline, and related compounds(1986)5 cited
• → ChemInform Abstract: STUDIES ON QUINOLINE AND ISOQUINOLINE DERIVATIVES. I. CONDENSATION OF QUINOLINE AND ISOQUINOLINE N‐OXIDES WITH ISOXAZOLES(1979)
• → ChemInform Abstract: STUDIES ON QUINOLINE AND ISOQUINOLINE DERIVATIVES. VIII. HYDRATION AND HYDROGENATION OF ETHYNYL SUBSTITUENTS ATTACHED TO THE PYRIDINE MOIETY OF QUINOLINE AND ISOQUINOLINE RINGS(1982)