Dirhodium Carboxylates Catalyzed Enantioselective Coupling Reactions of α‐Diazophosphonates, Anilines, and Electron‐Deficient Aldehydes

Chiral dirhodium carboxylate complexes (Rh(2)(S-PTAD)(4) or Rh(2)(S-PTTL)(4)) efficiently catalyze asymmetric three-component coupling reactions of α-diazophosphonates, anilines, and electron-deficient aldehydes to give α-amino-β-hydroxyphosphonates. The high level of enantiocontrol provides evidence for the intermediacy of metal-bound ammonium ylide in the product-forming step.