Synthesis of biheteroaryl derivatives by tetraphosphine/palladium-catalysed Suzuki coupling of heteroaryl bromides with heteroarylboronic acids

The synthesis of biheteroaryl derivatives by palladium-catalysed Suzuki cross-coupling reaction of heteroaryl bromides with heteroarylboronic acids is a challenging reaction due to the electronic and/or poisoning properties of these heteroaryl compounds. Through the use of [PdCl(C3H5)]2/cis,cis,cis-1,2,3,4-tetrakis(diphenylphosphinomethyl)cyclopentane as a catalyst, a range of heteroaryl bromides undergoes Suzuki reaction with heteroarylboronic acids such as thiophene-, furan- or pyridineboronic acid derivatives in good yields. This catalyst can be used at low loadings with several substrates. In general bromopyridines were found to be more reactive than bromothiophenes or bromofuranes.

The Tedicyp–palladium system proves to be an efficient catalyst for the coupling of heteroarylboronic acids with heteroaryl bromides. Since the electronic properties of heteroarylboronic acids appears to have a minor influence on the reactions rates, their coordinative/poisoning properties to palladium seems to have a decisive influence. On the other hand, the electronic properties of the heteroaryl bromide often have an important effect on the yields and rates of the reactions.Figure optionsDownload as PowerPoint slide