Noncatalyzedcoupling reactions of aryllithiums and haloarenes proceed not only through the well-known aryne route but also, in some cases, through a novel addition-elimination pathway. Indeed, ortho-chloro- and ortho-bromomethoxyarenes lead selectively to the corresponding ortho-biaryls through a chelation-driven aromaticnucleophilicsubstitutionpathway. Contrary to common belief, such noncatalyzed
Palladium catalyzed Suzuki–Miyaura coupling with aryl chlorides using a bulky phenanthryl N-heterocyclic carbene ligand
作者:Chun Song、Yudao Ma、Qiang Chai、Chanqin Ma、Wei Jiang、Merritt B. Andrus
DOI:10.1016/j.tet.2005.05.071
日期:2005.8
carbene (NHC) based palladium acetate catalyst was effective for the coupling of various aryl and vinyl chlorides with organoboron compounds. N,N-Bis-(2,9-dicyclohexyl-10-phenanthryl)-4,5-dihydroimidazolium chloride 8 (H2ICP·HCl) with Pd(OAc)2 and KF·18-c-6 in THF at room temperature gave Suzuki–Miyaura coupling of aryl and vinyl chorides, including unactivated and di-ortho substituted substrates in high