Scandium triflate-promoted addition of organozinc reagents to benzaldiminetricarbonylchromium derivatives

The reaction of benzaldiminetricarbonylchromium derivatives with organozinc reagents in the presence of scandium triflate afforded a single diastereomer of the corresponding amine complex exclusively. Even in the case of benzaldiminetri-carbonylchromium having an m-substituent of the aromatic ring, one diastereomer was obtained using the o-TMS-protected chromium complex. The TMS group and the chromium moiety were easily removed and the benzyl group was deprotected using HOOH and Pd to afford the corresponding amine.