Palladium on Carbon‐Catalyzed Cross‐Coupling using Triarylbismuths
Simple and efficient protocols for the 10% palladium on carbon (Pd/C)‐catalyzed cross‐coupling reactions between triarylbismuths and aryl halides have been developed. A variety of iodo‐ and bromobenzenes possessing an electron‐withdrawing group on the aromatic nucleus were smoothly cross‐coupled in the presence of 10% Pd/C, sodium phosphate dodecahydrate (Na3PO4⋅12 H2O) and 1,4‐diazabicyclo[2.2.2]octane (DABCO) in heated N‐methyl‐2‐pyrrolidone (NMP) as the solvent. For the arylations of iodobenzenes, the reactions effectively proceeded under the combined use of caesium fluoride (CsF) and 2,2′‐biquinoline. Furthermore, a ligand‐free 10% Pd/C‐catalyzed cross‐coupling reaction between the aryl iodides and triarylbismuths was also established by the addition of tetra‐n‐buthylammonium fluoride trihydrate (TBAF⋅3 H2O) in which the palladium metals were hardly leached from the catalyst into the reaction media.
Document Type: Research Article
Affiliations: Laboratory of Organic Chemistry, Gifu Pharmaceutical University, Gifu 501-1196, Japan, phone: (+81)-58-230-8109, Fax: (+81)-58-230-8109
Publication date: September 17, 2012