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