Asymmetric addition of a Reformatsky-type reagent to 3,4-dihydroisoquinoline N-oxides

Abstract

The asymmetric addition of a Reformatsky-type reagent, prepared in situ from diethylzinc and iodoacetic acid ester, to a carbon–nitrogen double bond in 3,4-dihydroisoquinoline N-oxides was achieved by utilizing diisopropyl ( R,R)-tartrate as a chiral auxiliary to afford the corresponding ( S)-1-substituted 2-hydroxy-1,2,3,4-tetrahydroisoquinolines with enantioselectivities up to 86% ee.