FICA, a new chiral derivatizing agent for determining the absolute configuration of secondary alcohols by 19F and 1H NMR spectroscopies
作者:Tamiko Takahashi、Hiroaki Kameda、Tomoyo Kamei、Jyunichi Koyanagi、Fabio Pichierri、Kenji Omata、Miyuki Ishizaki、Hiroshi Nakamura
DOI:10.1016/j.tetasy.2013.06.012
日期:2013.9
(FICA) was designed and prepared as its methyl ester for determining the absolute configuration of chiral molecules by both 1H and 19F NMR spectroscopies. Enantiomerically pure isomers of FICA methyl esters (FICA Me esters) were obtained by chromatographic separation using HPLC with a Daicel Chiralcel OJ-H column. The absolute configuration of the (+)-FICA Me ester was deduced to be (S) by X-ray crystallographic
设计并制备了光学活性的1-氟茚满-1-羧酸(FICA)作为其甲酯,用于通过1 H和19 F NMR光谱测定手性分子的绝对构型。通过使用Daicel Chiralcel OJ-H色谱柱的HPLC色谱分离,获得FICA甲酯(FICA Me酯)的对映体纯异构体。通过(R)-α-苯乙胺的(+)-FICA酰胺的X射线晶体学分析推论(+)-FICA Me酯的绝对构型为(S)。通过酯交换反应,两种对映异构体均衍生为手性仲醇的非对映体酯。在1 1 H NMR光谱,Δ的符号δ ħ(δ - [R - δ小号)分别对FICA分子平面的每侧保持一致。因此,改进的Mosher方法的概念可以成功地应用于基于FICA的过程。此外,在Δ符号的一致性δ ˚F(δ - [R - δ小号)值表明FICA方法是在分配基于仲醇的绝对构型可靠19 F NMR光谱。