has been shown that acid catalysis is more effective than base catalysts for the Friedlander annulation. In recent years, Bronsted and Lewis acids such as ionicliquids, sulfamic acid, hydrochloric acid, zirconium tetrakisdodecyl sulfate [Zr(DS)4], 29 silica sulfuric acid, silica supported phosphomolybdic acid [PMA.SiO2], 32 nanocrystalline aluminium oxide, dodecylphosphonic acid (DPA), poly(N-bromoethylbenzene-1
Quinolines have been synthesized in very good yields from 2-aminoarylketones and differently substituted carbonyl compounds in the presence of Yb(OTf)(3) as the catalyst. The method is applicable to both cyclic and acyclic carbonyl compounds with only slight differences in the experimental procedure. (C) 2011 Elsevier Ltd. All rights reserved.
Sustainable synthesis of N-heterocycles in water using alcohols following the double dehydrogenation strategy
first example of synthesis of pharmaceutically relevant N-heterocycles like substituted quinolines, acridines and 1,8-naphthyridines in water under air usingalcohols in presence of a new water soluble Ir-complex. The viability and efficiency of this approach was demonstrated by the efficient synthesis of biologically active natural product (±)-galipinine and gram scale synthesis of various N-heteroaromatics