Majority‐Rules‐Type Helical Poly(quinoxaline‐2,3‐diyl)s as Highly Efficient Chirality‐Amplification Systems for Asymmetric Catalysis

A highly efficient majority‐rules effect of poly(quinoxaline‐2,3‐diyl)s (PQXs) bearing 2‐butoxymethyl chiral side chains at the 6‐ and 7‐positions was established and attributed to large Δ G h values (0.22–0.41 kJ mol −1 ), which are defined as the energy difference between P ‐ and M ‐helical conformations per chiral unit. A PQX copolymer prepared from a monomer derived from ( R )‐2‐octanol (23 %  ee ) and a monomer bearing a PPh 2 group adopted a single‐handed helical structure (>99 %) and could be used as a highly enantioselective chiral ligand in palladium‐catalyzed asymmetric reactions (products formed with up to 94 %  ee ), in which the enantioselectivity could be switched by solvent‐dependent inversion of the helical PQX backbone.