Long-Distance Propagation of Stereochemical Information by Stereoselective Synthesis of Copper(I) Bipyridine Helicates

Several chiral ligands have been obtained by linking two achiral chains containing up to three bipyridine units to various dissymmetric templates. Addition of copper(I) and silver(I) ions resulted in the highly stereoselective formation of bis(helicates), the absolute configuration of which was dictated by that of the templates, with (P) or (M) helicates being formed from (R) or (S) templates, respectively. In the cases of ligands containing three bipyridine units, the stereochemical information was transferred from the templates to the helicates over a distance of about 20 A.