Stereocontrolled Ring-Opening of a Hindered Sulfamidate with Nitrogen-Containing Aromatic Heterocycles: Synthesis of Chiral Quaternary Imidazole Derivatives
作者:Lara Mata、Gonzalo Jiménez-Osés、Alberto Avenoza、Jesús H. Busto、Jesús M. Peregrina
DOI:10.1021/jo200479y
日期:2011.5.20
α-methylisoserine as an electrophile in a nucleophilic displacement reaction with nitrogen-containing aromatic heterocycles. Several imidazoles and pyrazole were tested as nucleophiles in the absence of an additional base to give the corresponding ring-opening compounds. We show that the process takes place by inversion of the configuration of the quaternary electrophilic center, retaining the enantiomeric excess
本文探讨了α-甲基异丝氨酸衍生的受阻环氨基磺酸盐作为亲电子在与含氮芳族杂环的亲核取代反应中的作用。在不存在额外碱的情况下,测试了几种咪唑和吡唑作为亲核试剂,以给出相应的开环化合物。我们表明该过程是通过反转四级亲电中心的构型而发生的,保留了对映体过量的起始氨基磺酸盐。此反应将打开,以获得重要的季咪唑衍生物的方法,例如作为一种创新型双-氨基至histidinoalanine相关酸和一种新颖的α,α-二取代的β氨基酸(β的2,2-氨基酸)。