Catalyst controlled regioselective Suzuki cross-coupling of 2-(4-bromophenyl)-5-chloropyrazine

The Suzuki cross-coupling between 2-(4-bromophenyl)-5-chloropyrazine and a range of aryl boronic acids has been investigated. The regioselectivity of the reaction can be switched between the aryl bromide and pyrazinyl chloride positions by changing the ligand associated with the palladium catalyst. Xantphos has shown excellent selectivity for the pyrazinyl chloride, with most other ligands showing preferential selectivity for the aryl bromide.