title: Rhodium-catalyzed asymmetric aqueous Pauson-Khand-type reaction.
abstract: An interesting rhodium-catalyzed asymmetric aqueous Pauson-Khand-type reaction was developed. A chiral atropisomeric dipyridyldiphosphane ligand was found to be highly effective in this system. This operationally simple protocol allows both catalyst and reactants to be handled under air without precautions. Various enynes were transformed to the corresponding bicyclic cyclopentenones in good yield and enantiomeric excess (up to 95 % ee). A study of the electronic effects of the enyne substrates revealed a correlation between the electronic properties of the substrates and the ee value obtained in the product of the Pauson-Khand-type reaction. A linear free-energy relationship was observed from a Hammett study.
authors.affiliation: Open Laboratory of Chirotechnology of the Institute of Molecular Technology for Drug Discovery and Synthesis, Department of Applied Biology and Chemical Technology, Hong Kong Polytechnic University, Hung Hom, Hong Kong. bcfyk@inet.polyu.edu.hk
authors.forename: Fuk Yee
authors.initials: FY
authors.lastname: Kwong
authors.forename: Yue Ming
authors.initials: YM
authors.lastname: Li
authors.forename: Wai Har
authors.initials: WH
authors.lastname: Lam
authors.forename: Liqin
authors.initials: L
authors.lastname: Qiu
authors.forename: Hang Wai
authors.initials: HW
authors.lastname: Lee
authors.forename: Chi Hung
authors.initials: CH
authors.lastname: Yeung
authors.forename: Kin Shing
authors.initials: KS
authors.lastname: Chan
authors.forename: Albert S C
authors.initials: AS
authors.lastname: Chan
mesh_terms: D000480:Alkynes / Q000737:chemistry; D002384:Catalysis; D003500:Cyclization; D006571:Heterocyclic Compounds / Q000138:chemical synthesis*; D008956:Models, Chemical; D015394:Molecular Structure; D012238:Rhodium / Q000737:chemistry*; D014867:Water / Q000737:chemistry*
chemical_list: D000480:Alkynes; D006571:Heterocyclic Compounds; D014867:Water; D012238:Rhodium