was examined by 2D NOESY and single-crystal X-ray analysis. In all cases the central chirality at boron was found to correlate with the chirality of the pseudoephedrine derivative; that is, with (1S,2S)-pseudoephedrine or (1S,2S)-N-methylpseudoephedrine the SB isomer was formed, while (1R,2R)-pseudoephedrine led to RB chirality at boron. Finally, a sample of enantiomerically pure Rp-2 was reacted with
研究了通过手性伪
麻黄碱衍
生物络合拆分平面手性双齿
路易斯酸Fc [B(Cl)Me] [SnMe 2 Cl](Fc = 1,2-
二茂铁基)(1)的方法。首先通过用Me 3 SiOMe处理将化合物1转化为甲氧基衍
生物Fc [B(OMe)Me] [SnMe 2 Cl](2)。后者通过多核NMR和单晶X射线衍射分析得到充分表征,这两者都表明B(OMe)Me取代基的氧与相邻的
锡中心之间存在显着的相互作用。在
甲醇释放下,与(1 S,2 S)-伪
麻黄碱的络合在室温顺利进行,但得到R的1:1混合物p和S p络合物,即使使用伪
麻黄碱也是如此。通过分级结晶分离复合物,并通过多核NMR,2D NOESY和X射线晶体学分析。相反,在空间上要求更高的
配体N-甲基伪
麻黄碱(MPE)可以实现高度立体选择性的络合。的反应2与0.5当量的(1小号,2小号) -衍
生物,得到的复合物与小号p - 2,留下未络合的异构体后面- [R