Aminal–Pyrrolidine Organocatalysts – Highly Efficient and Modular Catalysts for α‐Functionalization of Carbonyl Compounds

The substitution of the 4‐position of hydroxyproline by aphenol group, together with an aminal on the 2‐position, gave a synergistic effect leading to two powerful complementary organocatalysts. They show excellent enantiocontrol in the α‐functionalization of a wide range of linear/branched aldehydes and ketones, including Michael additions to ethenediyl disulfones or nitrostyrene and α‐amination. We obtained ees up to 98.5 % with low catalyst loadings (down to 1 mol‐%). As a proof of efficiency, TOFs of up to 1000 h–1 could be obtained.