Variation of Xantphos-Based Ligands in the Palladium-Catalyzed Reaction of Aryl Halides with Ureas
摘要:
A series of Xantphos-based ligands containing various substituents in the diphenylphosphino groups were synthesized, and their effect on the product yield and ratio in the palladium-catalyzed arylation of ureas with nonactivated aryl halides was studied. The arylation of urea and phenylurea in the presence of Pd-2(dba)(3)-CHCl3, 3,5-(CF3)(2)Xantphos, and Cs2CO3 in dioxane at 100degreesC gave the corresponding N,N'-diaryl-ureas in 62-98% yield.