Addition of Highly Polarized Organometallic Compounds to N-tert-Butanesulfinyl Imines in Deep Eutectic Solvents under Air: Preparation of Chiral Amines of Pharmaceutical Interest

We first report that highly polarized organometallic compounds of s-block elements add smoothly to chiral N-tertbutanesulfinyl imines in the biodegradable D-sorbitol/choline chloride eutectic mixture, thereby granting access to enantioenriched primary amines after quantitatively deblocking the sulfinyl group. The practicability of the methodology was further highlighted by (a) working at ambient temperature and under air, (b) very short reaction times (2 min), (c) the preparation of diastereomeric sulfinamides in very good yields (74–98%) and with a broad substrate scope, (d) the possibility of scaling up the process, and (e) the asymmetric synthesis of both the chiral amine side-chain of (R,R)-Formoterol (96% ee) and the pharmaceutically relevant (R)-Cinacalcet (98% ee).