Intramolecular C-H insertion catalyzed by dirhodium(II) complexes using CO 2 as the reaction media

Abstract

In this work, the intramolecular C-H insertion of diazoacetamides catalyzed by dirhodium(II) complexes and using CO 2 as solvent is disclosed. The expected lactams were obtained in yields over 97%. The asymmetric intramolecular C-H insertion was also achieved and the β-lactam 14 was obtained in >97% yield and 65% ee using the chiral dirhodium(II) catalyst Rh 2(S-PTTL) 4. Finally, the dirhodium(II) complex Rh 2(OAc) 4 was used in two consecutive cycles in which complete conversion to the lactam was observed. © 2012 Copyright Taylor and Francis Group, LLC.