Sc<sup>3+</sup>-Catalyzed Aldol-Type Additions of <i>N</i>-Benzoylcyclopropanecarboxamides via Iodide-Mediated Ring-Opening: Stereoselective Synthesis of γ-Lactams
作者:Sean H. Wiedemann、Hidetoshi Noda、Shinji Harada、Shigeki Matsunaga、Masakatsu Shibasaki
DOI:10.1021/ol800401g
日期:2008.4.1
A new catalytic aldol-type addition of cyclopropanecarboximides to aldehydes via iodide-mediated ring-opening is presented. The reaction was found to be catalyzed at 0 degrees C using either a Sc(OTf)3/NaI system or ScI3. Stereoselective formation of alpha,alpha-disubstituted enolates occurred in situ. gamma-Lactams bearing alpha-carbonyl quaternary stereocenters were obtained in 97-57% yield and dr
提出了通过碘化物介导的开环向醛类中催化新的醛丙型环丙烷碳酰亚胺加成反应。发现该反应使用Sc(OTf)3 / NaI系统或ScI 3在0℃催化。立体选择性地形成α,α-二取代的烯酸酯。闭环后,获得具有α-羰基季立体中心的γ-内酰胺,收率为97-57%,dr = 90:10-80:20。