A straightforward route toward construction of α-quaternary chiral β-lactam moiety via Rh(II)/Pd(0)-catalyzed stereoselective relay catalytic reaction is reported. This asymmetric dual relay catalysis involves Rh(II)-catalyzed enantioselective intramoluecular C-H insertions of α-diazoamides, and sequential Pd(0)-catalyzed diastereoselective intermolecular allylic alkylation. Under mild reaction conditions, a broad range of α-quaternary allylated chiral β-lactams have been synthesized in high yields (up to 99%) with excellent stereoselectivities [up to diastereomeric ratio (dr) >99:1, up to 98% enantiomeric excess (ee)].
Bibliographical noteFunding Information:
This work was made possible through financial support by the Samsung Science and Technology Foundation (SSTF-BA1401-10). We thank Dr. Y. Kim for X-ray analysis and Dr. U. Kim for critical reading of this manuscript at NanoBio Institute, Ewha Womans University.
Copyright © 2018 American Chemical Society.
- C-H insertion
- allylic alkylation
- asymmetric catalysis