title: Iridium-Catalyzed Asymmetric Ring-Opening of Oxabenzonorbornadienes with N-Substituted Piperazine Nucleophiles.
abstract: Iridium-catalyzed asymmetric ring-opening of oxabenzonorbornadienes with N-substituted piperazines was described. The reaction afforded the corresponding ring-opening products in high yields and moderate enantioselectivities in the presence of 2.5 mol % [Ir(COD)Cl]₂ and 5.0 mol % (S)-p-Tol-BINAP. The effects of various chiral bidentate ligands, catalyst loading, solvent, and temperature on the yield and enantioselectivity were also investigated. A plausible mechanism was proposed to account for the formation of the corresponding trans-ring opened products based on the X-ray structure of product 2i.
authors.affiliation: Key Laboratory of Theoretical Chemistry of Environment, Ministry of Education, School of Chemistry and Environment, South China Normal University, Guangzhou 510006, China. 18971194938@yeah.net.
authors.forename: Wen
authors.initials: W
authors.lastname: Yang
authors.affiliation: School of Pharmaceutical Sciences, Gannan Medical University, Yi Xue Yuan Road, Ganzhou 341000, China. luorenshi2010@163.com.
authors.forename: Renshi
authors.initials: R
authors.lastname: Luo
authors.affiliation: Key Laboratory of Theoretical Chemistry of Environment, Ministry of Education, School of Chemistry and Environment, South China Normal University, Guangzhou 510006, China. yangdq@scnu.edu.cn.
authors.forename: Dingqiao
authors.initials: D
authors.lastname: Yang
mesh_terms: D001897:Boronic Acids / Q000737:chemistry*; D002384:Catalysis; D018360:Crystallography, X-Ray; D007495:Iridium / Q000737:chemistry*; D015394:Molecular Structure; D009636:Norbornanes / Q000737:chemistry*; D000077489:Piperazine; D010879:Piperazines / Q000737:chemistry*; D013237:Stereoisomerism
chemical_list: D001897:Boronic Acids; D009636:Norbornanes; D010879:Piperazines; D000077489:Piperazine; D007495:Iridium
keywords: N-substituted piperazines; asymmetric ring-opening; chiral bisphosphine ligand; iridium catalyst; oxabenzonorbornadiene