Tandem conjugate addition/α-alkylation of lithiated chiral α-amino nitriles 3 and alkyl bromides to 2-cyclohexenone afforded 2-substituted 3-aroylcyclohexanones 5 of high diastereo- and enantiomeric purity (de ≥98%, ee ≥97-≥99%) and in good overall yields. The absolute configuration of the new stereogenic centres was determined by X-ray structure analysis of the Michael adduct 4c.
用
锂化手性δ-
氨基腈 3 和烷基
溴化物与 2-
环己酮进行串联共轭加成/δ-烷基化反应,得到了 2-取代的 3-芳酰基
环己酮 5,其非对映纯度和对映体纯度都很高(de ≥98%,ee ≥97-≥99%),总产率也很高。通过对迈克尔加合物 4c 进行 X 射线结构分析,确定了新立体中心的绝对构型。