Three‐Component Asymmetric Mannich Reaction Catalyzed by a Lewis Acid with Rhodium‐Centered Chirality

A highly efficient direct asymmetric three‐component Mannich reaction of an N ‐acylpyrazole, an aldehyde and a primary or secondary amine, was enabled by a rhodium‐based Lewis‐acid catalyst with metal‐centered chirality. Excellent enantioselectivities were achieved for a variety of substrates at a typical catalyst loading of merely 0.5 mol % (23 examples, up to 98 % ee ).