Chiral reductions of imines leading to the syntheses of optically active

Abstract

A process for preparing an R enantiomer of a compound of the formula (I): ##STR1## wherein Ar is 3-methoxyphenyl, 3-chlorophenyl, or 1-naphthyl, and X is independently selected from the group consisting of H, F, Cl, Br, I, phenyl, CF.sub.3, CF.sub.2 H, CFH.sub.2, lower alkyl (e.g., Me), O-lower alkyl (e.g., OMe), OCH.sub.2 CF.sub.3, OH, CN, NO.sub.2, C(O)-lower alkyl (e.g., C(O)Me), C(O)O-lower alkyl (e.g., C(O)OMe), C(O)NH-lower alkyl (e.g., C(O)NH--Me), C(O)N-lower alkyl.sub.2 (e.g., C(O)NMe.sub.2), OC(O)-lower alkyl (e.g., OC(O)Me), and NH--C(O)-lower alkyl (e.g., NH--C(O)Me), where 'lower alkyl' is selected from a group consisting of 1 to 6 carbon atoms, and m is an integer between 1 and 5, by asymmetrically and enantioselectively reducing an imine with a reducing agent/chiral auxiliary agent complex so as to produce an enantiomeric excess of R enantiomer of the compound of formula (I) over the S enantiomer of the compound of formula (I). The process is especially useful to produce compounds (R)-(+)-N-[1-(3-methoxyphenyl)ethyl]-3-(2-chlorophenyl)propanamine and (R)-(+)-N-[1-(3-methoxyphenyl)ethyl]-3-(phenyl)propanamine. Enantiomeric excess of the R enantiomer over S enantiomer of greater than 65% have been achieved.