Tiffner Maximilian, Novacek Johanna, Busillo Alfonso, Gratzer Katharina, Massa Antonio, Waser Mario
Institute of Organic Chemistry, Johannes Kepler University Linz, Altenbergerstraße 69, 4040 Linz, Austria.
Department of Chemistry and Biology, University of Salerno, 84084-Fisciano, Italy.
RSC Adv. 2015 Aug 28;5(96):78941-78949. doi: 10.1039/C5RA14466C.
Bifunctional chiral urea-containing quaternary ammonium salts can be straightforwardly synthesised in good yield and with high structural diversity a scalable and operationally simple highly telescoped sequence starting from -1,2-cyclohexanediamine. These novel hybrid catalysts were systematically investigated for their potential to control glycine Schiff bases in asymmetric addition reactions. It was found that Michael addition reactions and the herein presented aldol-initiated cascade reaction can be carried out to provide enantiomeric ratios up to 95 : 5 and good yields under mild conditions at room temperature.
含双功能手性脲的季铵盐可从-1,2-环己二胺出发，通过一个可扩展且操作简单的高度串联序列直接以良好的产率和高结构多样性合成。对这些新型杂化催化剂在不对称加成反应中控制甘氨酸席夫碱的潜力进行了系统研究。结果发现，迈克尔加成反应以及本文所介绍的醛醇引发的级联反应可以在室温温和条件下进行，提供高达95:5的对映体比例和良好的产率。
