Iridium(I)-Catalyzed Regio- and Enantioselective Allylic Amidation.
Ir(I)-catalyzed intermolecular allylic amidation of ethyl allylic carbonates with soft nitrogen nucleophiles under completely "salt-free" conditions is described. A combination of [Ir(COD)Cl](2), a chiral phosphoramidite ligand L*, and DBU as a base in THF effects the reaction. The reaction appears to be quite general, accommodating a wide variety of R-groups and soft nitrogen nucleophiles, and proceeds with excellent regio- and enantioselectivities to afford the branched N-protected allylic amines. The developed reaction was conveniently utilized in the asymmetric synthesis of Boc protected alpha- and beta-amino acids as well as (-)-cytoxazone.
Singh
Om V
OV
Department of Chemisry, The University of Texas at San Antonio, One UTSA Circle, San Antonio, TX 78249, USA.
Han
Hyunsoo
H