The first example of the use of ionic liquids as reaction media in an asymmetric Pd(II)-catalysed oxycarbonylation was investigated. Based on a ligand screening, the chiral box-type ligands were successfully used in the Pd(II)-promoted bicyclisation of pent-4-ene-1,3 diol (±)-1. The kinetic resolution of (±)-1 in the presence of a chiral catalyst, p-benzoquinone and acetic acid in ionic liquids under a carbon monoxide atmosphere afforded enantioenriched 2,6-dioxabicyclo[3.3.0]octane-3-ones (S,S)-2 (80% ee) and (R,R)-2 (57% ee).
研究人员首次在不对称
钯(II)催化的氧羰基化反应中使用
离子液体作为反应介质。在
配体筛选的基础上,成功地将手性盒型
配体用于 Pd(II)-promoted bicyclisation of pent-4-ene-1,3 diol (±)-1。在手性催化剂、
对苯醌和
乙酸存在下,(±)-1 在
一氧化碳气氛下于
离子液体中进行动力学解析,得到了对映体富集的 2,6-二氧双环[3.3.0]
辛烷-3-酮 (S,S)-2 (80% ee) 和 (R,R)-2 (57% ee)。