Axial chirality control during Suzuki-Miyaura cross-coupling reactions: the tert-butylsulfinyl group as an efficient chiral auxiliary.

An efficient route to a new family of axially chiral biaryl ligands by a Suzuki-Miyaura cross-coupling reaction between ortho,ortho'-disubstituted aryl iodides bearing in ortho position a tert-butyl or p-tolylsulfinyl group and ortho-substituted phenyl boronic acids or esters is described. The comparison between the t-BuSO and p-TolSO groups as chiral controllers is reported. The modularity of the approach is demonstrated by the preparation of a variety of enantiopure axially chiral mixed S/N and S/P ligands.