作者:Susan Lühr、Jens Holz、Odalys Zayas、Volkmar Wendisch、Armin Börner
DOI:10.1016/j.tetasy.2012.08.010
日期:2012.9
α-aminomethylacrylates used as substrates were prepared by a Baylis–Hillman reaction, followed by acylation and amination. For the asymmetric hydrogenation, a large variety of chiral, preferentially rhodium catalysts bearing commercially available phosphorus ligands were tested. Conversions and enantioselectivities were dependent on the reaction conditions and varied strongly between the substrates used. A chiral
手性β的合成2 -氨基酸由均相不对称氢化进行了讨论。通过Baylis-Hillman反应制备用作底物的前手性β-芳基-或β-杂芳基-α- N-苄基/ N-乙酰基/ N -Boc取代的α-氨基甲基丙烯酸酯,然后进行酰化和胺化反应。对于不对称氢化,测试了带有市售磷配体的多种手性,优选铑催化剂。转化率和对映选择性取决于反应条件,并且在所用的底物之间变化很大。手性N-α-苯乙基支持手性催化剂的立体辨别能力,因此可以实现匹配对效应。与之形成强烈对比的是,手性酯基在这方面几乎没有作用。在某些情况下,与使用其酯相比,使用相应的底物酸更好。在优化氢化条件(手性催化剂,H 2压力,温度,溶剂)后,可实现完全转化和ee高达99%的产物。