title: Stereoselective pinacol coupling of chiral formylferrocene using divalent samarium triflate: preparation of a new chiral bisferrocenyl oxazoline ligand and its application to asymmetric Diels-Alder reactions.
abstract: [reaction: see text] The pinacol coupling reaction of planar chiral ortho-oxazoline-substituted formylferrocene was smoothly mediated by SmI2 or Sm(OTf)3 to give the (R,R) isomer selectivity (up to 76% diastereomeric excess). The combination of Yb(OTf)3 and the (R,R)-ferrocenyl diol was revealed to be a good catalyst for the asymmetric Diels-Alder reaction of 3-acyloxazolidinone with cyclopentadiene, and the endo adduct was produced in up to 80% enantiomeric excess.
authors.affiliation: Department of Applied Chemistry, Institute of Science and Engineering, Chuo University, Kasuga, Bunkyo-ku, Tokyo 112-8551, Japan. fukuzawa@chem.chuo-u.ac.jp
authors.forename: Shin-ichi
authors.initials: S
authors.lastname: Fukuzawa
authors.forename: Yuusuke
authors.initials: Y
authors.lastname: Yahara
authors.forename: Akira
authors.initials: A
authors.lastname: Kamiyama
authors.forename: Masumi
authors.initials: M
authors.lastname: Hara
authors.forename: Satoshi
authors.initials: S
authors.lastname: Kikuchi