Rh-Catalyzed Asymmetric Conjugate Addition of Arylboronic Acids to 3-Arylpropenoates: Enantioselective Synthesis of (R)-Tolterodine

A highly enantioselective conjugate addition of arylboronic acids to 3-arylpropenoates is presented. The rhodium complexes obtained from deoxycholic acid derived binaphthyl phosphites showed good activity as well as very high enantioselectivity (ee up to 99 %) in the conjugate addition to different ethyl-3-arylpropenoates, allowing to obtain useful chiral building blocks for the synthesis of active pharmaceutical ingredients. The method was applied to the enantioselective synthesis of the antimuscarinic drug (R)-tolterodine.