Organocatalytic asymmetric allylic carbon–carbon bond formation

Abstract

Organocatalytic allylic C–C bond-forming addition of activated alkylidenes to alkyl and aryl nitroalkenes has been achieved with high diastereo- and enantioselectivity. Chiral tertiary amine catalysts are used to give allyl intermediates which exhibit γ-selectivity in the C–C bond forming step. The reactions proceed with up to >99 : 1 syn : anti ratio for both the alkyl- and aryl nitroalkenes with up 96% and 98% ee, respectively. The products of this conjugate addition are transformed into a range of intermediates, such as optically active conjugated dienes and 1-substituted tetralones, which are difficult to access via alternative methods.