N-Pyrrolidine-2-ylmethyl)-2-hydroxy-3-aminopinanes as novel organocatalysts for asymmetric conjugate additions of ketones to α-nitroalkenes

Novel stereoisomeric natural pinane-derived bifunctional catalysts 3a-d bearing a pyrrolidine unit have been synthesized and examined in the asymmetric conjugate additions of carbonyl compounds to α-nitroalkenes. Six-membered cyclic ketones react with β-nitrostyrene derivatives in the presence of (1R,2R,3R,5R)-2-hydroxy-3-((S)-pyrrolidin-2-ylmethylamino) pinane 3b (10 mol %) with high conversion to afford with diastereoselectivity (dr (syn/anti) up to 97/3), the corresponding Michael adducts with enantiomeric purities of up to 88% ee.