A comparative study of the palladium-catalyzed arylationand heteroarylation of 5-bromoazolopyrimidines shows thataryl and electron-rich heteroaryl boronic acids gave higheryields than those obtained using the corresponding aryl andheteroaryl tributyl stannanes. In contrast, the reaction withelectron-poor heteroaryl tributyl stannanes gave better resultsthan the corresponding boronic acids.
