Paderes Monissa C, Chemler Sherry R
Department of Chemistry, University at Buffalo, The State University of New York, 618 Natural Sciences Complex, Buffalo, New York 14260, USA.
Org Lett. 2009 May 7;11(9):1915-8. doi: 10.1021/ol9003492.
The diastereoselectivity of the copper-promoted intramolecular aminooxygenation of various alkene substrates was investigated. Alpha-substituted 4-pentenyl sulfonamides favor the formation of 2,5-cis-pyrrolidines (dr >20:1) giving excellent yields which range from 76-97% while gamma-substituted substrates favor the 2,3-trans pyrrolidine adducts with moderate selectivity (ca. 3:1). A substrate whose N-substituent was directly tethered to the alpha-carbon exclusively yielded the 2,5-trans pyrrolidine. The synthetic utility of the method was demonstrated by a short and efficient formal synthesis of (+)-monomorine.
研究了铜促进的各种烯烃底物分子内氨氧化反应的非对映选择性。α-取代的4-戊烯基磺酰胺有利于2,5-顺式吡咯烷的形成(非对映体比例>20:1),产率优异,范围为76-97%,而γ-取代的底物有利于形成具有中等选择性(约3:1)的2,3-反式吡咯烷加合物。一种N-取代基直接连接到α-碳上的底物只生成2,5-反式吡咯烷。通过对(+)-单莫林进行简短而有效的形式合成,证明了该方法的合成实用性。