One-pot synthesis of quinoline-4-carboxylic acid derivatives in water: Ytterbium perfluorooctanoate catalyzed Doebner reaction

Ytterbium perfluorooctanoate [Yb(PFO)(3)] has been proved to be an efficient catalyst for Doebner reaction of pyruvic acid, aldehydes and amines under mild conditions in water to afford quinoline-4-caboxylic acid derivatives with three component one-pot method in good yields. The process is operationally simple and environmentally benign and the catalyst has readily been recycled for several times with consistent activity. Furthermore, a plausible mechanism for this transformation is also presented. (C) 2009 Elsevier B.V. All rights reserved.