Enantioselective synthesis of (R)-tolterodine via CuH-catalyzed asymmetric conjugate reduction.

An efficient and highly enantioselective method for the preparation of (R)-tolterodine is described. The synthesis was performed by CuH-catalyzed asymmetric conjugate reduction of a beta,beta-diaryl-substituted unsaturated nitrile as a key step, which is prepared by a stereoselective hydroarylation of alkynenitrile with aryl boronic acid. The synthesis was accomplished without employing the protection-deprotection sequence.