lridium/N-Heterocyclic Carbene Complex-Catalyzed Intermolecular Allylic Alkylation Reaction

摘要

N-Heterocyclic carbenes (NHCs) were found to be suitable ligands in Ir-catalyzed intermolecular allylic alkylation reaction. In the presence of a catalyst derived from [Ir(dncot)Cl](2) (dncot = dinaphthocyclooctatetraene) and triazolium salt L7, the alkylation products from the reaction of aryl allyl carbonates with sodium dialkyl malonates could be obtained in 85-99% yields favoring the formation of branched products (90/10 - 99/1 b/l). In addition, chiral dihydroisoquinoline-type NHC (DHIQ-NHC) (L8) is successfully applied in Ir-catalyzed asymmetric allylic alkylation reactions. Excellent enantioselectivities and moderate regioselectivities were obtained for a wide range of substrates.