Generation and asymmetric Michael addition reaction of chirally N- protected α-aminoalkyl cyanocuprates

Enantio-enriched α-aminopropylcyanocuprates, generated from the chirally N-protected α-aminopropylstannane (racemic at the Sn-bearing stereocenter) via Pearson's Sn/Li transmetalation protocol followed by treatment with copper cyanide, is shown to undergo an addition reaction to α,β-unsaturated aldehydes and ketones to give the γ-amino carbonyl compounds in higher stereoselective fashion. Of special interest is the reaction with acrolein and 2-cyclohexenone which affords the adducts as a single stereoisomer.