Highly stereoselective iminopinacol coupling of chiral aromatic imines derived from di- and tripeptides

The reduction of aromatic imines prepared from (S)-Ile-(S)-Ile-OMe, (S)-Val-(S)-Val-OMe, and (S)-Val-(S)-Val-(S)-Val-OMe with Zn-MsOH in THF gave C2-symmetric (R,R)-diamines in high yields and stereoselectivities.