Highly Enantioselective Synthesis of gamma-Nitro Heteroaromatic Ketones in a Doubly Stereocontrolled Manner Catalyzed by Bifunctional Thiourea Catalysts Based on Dehydroabietic Amine: A Doubly Stereocontrolled Approach to Pyrrolidine Carboxylic Acids

A new class of dehydroabietic amine-substituted primary amine-thiourea bifunctional catalysts were designed and synthesized. The doubly stereocontrolled organocatalytic conjugate addition of a variety of heterocycles-bearing ketones to nitroalkenes was Investigated for the first time, affording (S)- or (R)-gamma-nitro heteroaromatic ketones with excellent enantioselectivities (up to ee >99%). Furthermore, the nearly optically pure gamma-nitro heteroaromatic ketones can be readily transformed into chiral pyrrolidine carboxylic acids.