Tetraphosphine/palladium-catalysed Suzuki cross-coupling with sterically hindered aryl bromides and arylboronic acids

cis,cis,cis-1,2,3,4-Tetrakis(diphenylphosphinomethyl)cyclopentane/[PdCl(C3H5)]2 system efficiently catalyses the Suzuki cross-coupling of sterically hindered substrates. Very high turnover numbers can be obtained for the coupling of sterically hindered aryl bromides with benzeneboronic acid or for the coupling of bromobenzene with sterically hindered arylboronic acids. On the other hand the formation of tri-ortho-substituted biaryl adducts requires higher catalyst loading.