Abstract.Ephedrine can be readily converted by means of intramolecular S,2 substitution by the hydroxyl or amino substituent into, respectively, the corresponding epoxide or aziridine with high stereocontrol. Subsequent stereoselective ring opening at the benzylic centre using tetrabutylammonium fluoride (TBAF) and dithiols affords the C , symmetrical hydroxy or amino sulfides in excellent yield. Application of these ligands in a palladium-catalyzed asymmetric allylic substitution reaction gave moderate to high enantiomeric excesses (up to 79%) and high yields of product.New methodologies for catalytic enantioselective synthesis open the perspective of synthesis of chiral non-racemic materials at both lower economic and environmental cost'.A popular as well as rational approach to the control of stereoselectivity in transition metal catalyzed reactions is based upon the use of ligands possessing only pure rotational symmetry elements, the most popular being the C, symmetrical ligands,. However, several successful non C, symmetrical catalysts have been developed in recent years3, including chiral, non-racemic @amino alcohols based upon cinchona and ephedra alkaloids4. The corresponding ephedra based p-amino thiols and sulfides are also interesting candidates but have attracted less attention, owing to the lack of straightforward and simple synthetic routes to suitable derivatives. We recently provided a solution to this problem via a new synthetic route to the thiol analogues 1 and 2 and the disulfides 3 as well as thiazolines 4 starting from readily available (IR,2S)-ephedrine and (lS,2S)-pseudoephedrine (Scheme l)5. These derivatives have been shown to catalyze the 1,2 addition of diethylzinc to aromatic aldehydes such as '' Dedicated to Professor Upendru Pundit on the occasion of his retirement from the
