Prolinate Salt as a Catalyst in the syn-Selective, Asymmetric Mannich Reaction of Alkynyl Imine.
Yujiro HayashiTatsuya YamazakiGenki KawauchiItaru SatoPublished in: Organic letters (2018)
Prolinate salt is an efficient catalyst in the Mannich reaction of alkynyl imine and aldehyde, to afford synthetically useful chiral propargyl amine derivatives with excellent syn-selectivity and nearly perfect control of the absolute configuration. The counterion of the prolinate salt does not affect the enantioselectivity. This is a rare example, in which proline alkali metals, alkaline-earth metals, or ammonium salt show higher reactivity and better stereoselectivity than the parent proline.