title: CAr-O Rotamers in 3,3'-Disubstituted BINOL Esters.
abstract: Rotamers around the CAr-O bond were disclosed in 3,3'-disubstituted BINOL esters by NMR spectroscopy. A bulky R1group increased the rotational barrier. The pivalate showed two rotamers at 2 °C, and broad signals were observed close to room temperature when R2= Ph. The highest rotational barrier was recorded for the (tetracyanocyclopentadienyl)carboxylate, and C-O rotamers were present at room temperature. DFT calculations indicated the presence of repulsion between R1and R2during rotation of the CAr-O bond.
authors.affiliation: Faculty of Pharmacy, Meijo University , 150 Yagotoyama, Tempaku-ku, Nagoya 468-8503, Japan.
authors.forename: Takeo
authors.identifier: 0000-0002-9006-8249
authors.initials: T
authors.lastname: Sakai
authors.affiliation: Faculty of Pharmacy, Meijo University , 150 Yagotoyama, Tempaku-ku, Nagoya 468-8503, Japan.
authors.forename: Junpei
authors.initials: J
authors.lastname: Matsuoka
authors.affiliation: Faculty of Pharmacy, Meijo University , 150 Yagotoyama, Tempaku-ku, Nagoya 468-8503, Japan.
authors.forename: Masayuki
authors.initials: M
authors.lastname: Shintai
authors.affiliation: Faculty of Pharmacy, Meijo University , 150 Yagotoyama, Tempaku-ku, Nagoya 468-8503, Japan.
authors.forename: Yuji
authors.initials: Y
authors.lastname: Mori