title: Heterobimetallic catalysis in asymmetric 1,4-addition of O-alkylhydroxylamine to enones.
abstract: A heterobimetallic YLi3tris(binaphthoxide) catalyst (YLB) promoted a 1,4-addition of O-methylhydroxylamine in high enantiomeric excess (up to 97% ee). Catalyst loading was reduced to as little as 0.5 mol %, still affording the 1,4-adduct in 96% yield and 96% ee. A high concentration of substrates and the scalability of the present system is also practically useful. The results suggested that the heterobimetallic catalysis was not deactivated even in the presence of excess amine under highly concentrated conditions. A Y and Li bimetallic cooperative function was essential for a high catalyst turnover number.
authors.affiliation: Graduate School of Pharmaceutical Sciences, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
authors.forename: Noriyuki
authors.initials: N
authors.lastname: Yamagiwa
authors.forename: Shigeki
authors.initials: S
authors.lastname: Matsunaga
authors.forename: Masakatsu
authors.initials: M
authors.lastname: Shibasaki
mesh_terms: D000475:Alkenes / Q000737:chemistry*; D002384:Catalysis; D006898:Hydroxylamines / Q000737:chemistry*; D007659:Ketones / Q000737:chemistry*; D008094:Lithium / Q000737:chemistry*; D009942:Organometallic Compounds / Q000737:chemistry*; D015018:Ytterbium / Q000737:chemistry*
chemical_list: D000475:Alkenes; D006898:Hydroxylamines; D007659:Ketones; D009942:Organometallic Compounds; D008094:Lithium; D015018:Ytterbium