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
Direct β-Alkenylation of Ketones via Pd-Catalyzed Redox Cascade
作者:Chengpeng Wang、Alexander J. Rago、Guangbin Dong
DOI:10.1021/acs.orglett.9b01116
日期:2019.5.3
A direct β-alkenylation of simple ketones with alkenyl bromides is reported via a Pd-catalyzed redox cascade strategy. The reaction is redox neutral and directing-group-free, in the absence of strong acids or bases. Both cyclic and linear ketones are suitable substrates, and various alkenyl bromides can be coupled. The resulting β-alkenyl ketones are readily derivatized through diverse alkene functionalization
Reactions of carbonyl compounds in basic solutions. Part 32.1 The Perkin rearrangement
作者:Keith Bowden、Sinan Battah
DOI:10.1039/a801538d
日期:——
relatively rapid base-catalysed ring fission of the 3-halocoumarins to give (E)-2-halo-3-(2-hydroxyphenyl)acrylic acids. Rate coefficients have been measured for the base-catalysed ring fission of 6-substituted and 4-methyl-3-bromocoumarins and of 3-chlorocoumarin in 70% (v/v) dioxane–water at various temperatures. The second stage is a relatively slow cyclisation process. Rate coefficients have been measured
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
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