of aryl iodides were coupled with aromatic and aliphatic terminal alkynes to give the corresponding 1,2-disubstituted aromatic alkynes in good yields by using only 0.4 mol % of the heterogeneous 10 % Pd/C as the catalyst without a ligand, copper salt, or amine in an aqueous medium.
Easy Copper-, Ligand- and Amine-Free Sonogashira Coupling Reaction Catalyzed by Palladium on Carbon at Low Catalyst Loading and by Exposure to Air
作者:Guolin Zhang
DOI:10.1055/s-2005-863720
日期:——
An easy copper-, ligand and amine-free Sonogashira coupling reaction catalyzed by commercially available palladium on carbon with air at low catalyst loading (0.2 mol% Pd) has been developed. Aryl iodides coupled with aromatic alkynes gave good to excellent yields and with aliphatic alkyne gave moderate to good yields. The reaction system is easy to handle.
γ-Valerolactone (GVL) can be used as an efficient and practical alternative to the banned and commonly used dipolar aprotic solvents. In this contribution GVL has been used as a non-toxic, biodegradable, biomass-derived medium, for the definition of a simple and general protocol for the Sonogashira cross-coupling reaction. The chemical efficiency of GVL as a medium is excellent and the best results