Asymmetric Intramolecular CH Insertion of α-Diazoacetamides in Water by Dirhodium(II) Catalysts Derived from Natural Amino Acids

The asymmetric dirhodium(II)-catalyzed intramolecular CH insertion of α-diazo acetamides in water is described for the first time. The use of natural α-amino acids as chiral ligands allowed the preparation of novel dirhodium(II) homochiral complexes by a simple procedure consisting of the in situ ligand exchange starting from dirhodium tetraacetate. The catalytic system was further reused up to 7 cycles and β-lactams were obtained in good yields and enantiomeric excess.