Synthesis of Atropisomeric Heterotopic S-Donor Ligands through Asymmetrization of C2-Symmetry 2,2'-Disostituted 1,1'-Binaphthalene Derivatives

Useful synthetic procedures for the conversion of C2 symmetry 1,1'-binaphthalene-2,2'-dithiol (BINAS) and 1,1'-binaphthalene-2,2'-diol (BINOL) into heterotopic S,S'- and heterodonor O,S-chelating atropisomeric ligands have been devised. Monoalkylation of the dithiol is successfully accomplished by asymmetrization of the corresponding dicarbamate through selective removal of one S-carbamoyl group, while asymmetrization of the diol can be more readily achieved by selective monoacylation