Axially Chiral Binaphthyl Surrogates with an Inner N−H−N Hydrogen Bond

详细信息    查看全文

• 作者：Takeo Kawabata ; Changsheng Jiang ; Kazuhiro Hayashi ; Kazunori Tsubaki ; Tomoyuki Yoshimura ; Swapan Majumdar ; Takahiro Sasamori ; Norihiro Tokitoh
• 刊名：Journal of the American Chemical Society
• 出版年：2009
• 出版时间：January 14, 2009
• 年：2009
• 卷：131
• 期：1
• 页码：54-55
• 全文大小：148K
• 年卷期：v.131,no.1(January 14, 2009)
• ISSN：1520-5126

文摘

Novel chiral binaphtyl surrogates with an inner hydrogen bond have been created. The NH appears at 13.0−13.3 ppm in thier ¹H NMR spectrum, indicating extremely strong hydrogen bonding. Enantiomers of these compounds were stable at ambient temperature and separable by HPLC with a chiral stationary phase. The half-lives of racemization of the enantiomer are in the range 3 months to 2 years at 20 °C, and the barriers for racemization are in the range 27.0 to 28.2 kcal/mol. An X-ray crystal analysis of the compound (R = CHPh₂) shows that the pseudonaphthyl skeleton including CN···HN is almost completely planar and the dihedral angle between the pseudonaphthalene and naphthalene rings is 128°.