Palladium-Catalyzed Coupling of 3-Halo-Substituted Coumarins, Chromenes, and Quinolones with Various Nitrogen-Containing Nucleophiles
作者:Mohamed Ali Soussi、Davide Audisio、Samir Messaoudi、Olivier Provot、Jean-Daniel Brion、Mouâd Alami
DOI:10.1002/ejoc.201100480
日期:2011.9
An efficient and general palladium-catalyzedcoupling reaction between 3-bromocoumarins, 3-bromoquinolin-2(1H)-ones, and 3-iodo-2H-chromenes with a variety of nitrogen-containingnucleophiles (azole, amide, lactam, sulfonamide, aniline, amine, and urea) is described. The reaction proceeded rapidly and cleanly in dioxane providing the coupling products in good to excellent yields. The chemoselectivity
A safe, convenient, and regioselective synthesis of 3-halo coumarins using a metal halide (CuX2 alone or with ZnX2) promoted halogenation with N-halosuccinimide (NXS) as halide source is reported. The synthesis involved the steady in situ generation of highly reactive positive halogen (X+) by the coordination of copper or zinc with the N-halosuccinimide and subsequent electrophilic aromatic substitution
Functionalized3-bromocoumarins 2 have been prepared by a simpleone-pot bromination/Wittig/cyclization tandem process from methyl (triphenylphosphoranylidene)acetate, N-bromosuccinimide and a series of 2-hydroxybenzaldehydes. Owing to the commercial availability of salicylaldehyde derivatives, this approach offers such a diverse range of compounds that it fulfills the recent demand for the generation
Direct C–H cross-coupling approach to heteroaryl coumarins
作者:Minsik Min、Bomi Kim、Sungwoo Hong
DOI:10.1039/c2ob07137a
日期:——
A Pd-catalyzed direct cross-coupling of 3-bromocoumarins with heteroarenes provided an efficient route to synthesizing 3-heteroarylcoumarins. The reaction scope for the transformation was fairly broad, affording modest to good yields of various 3-heteroarylcoumarin scaffolds, which are privileged structures and prevalent motifs in many biologically active compounds and fluorophores.
Palladium-Catalyzed Coupling of<i>N</i>-Aminoazoles with 3-Halo-Substituted Quinolin-2(1<i>H</i>)-ones, Coumarins, Quinoxalin-2(1<i>H</i>)-ones, and Chromenes
An efficient and general palladium-catalyzedcoupling of 3-bromoquinolin-2(1H)-ones, 3-bromocoumarins, 3-chloroquinoxalin-2(1H)-ones, and 3-iodo-2H-chromenes with a variety of 1-aminoazoles is described. The reaction proceeds cleanly in the presence of the Pd(OAc)2/4,5-bis(diphenylphosphino)-9,9-dimethylxanthene (Xantphos) catalytic system to provide the coupling products in good to excellent yields