作者:Leleti Rajender Reddy、Sonia G. Das、Yugang Liu、Mahavir Prashad
DOI:10.1021/jo902710s
日期:2010.4.2
A new and general method for asymmetric synthesis of either enantiomer of 2-substituted pyrrolidines from a single starting material is described. Reductive cyclization of (SS)-γ-chloro-N-tert-butanesulfinyl ketimines with LiBHEt3 in THF at −78 to 23 °C afforded (SS,R)-N-tert-butanesulfinyl-2-substituted pyrrolidines in excellent yields (88−98%) and with high diastereoselectivity (99:1). The diastereoselectivity
描述了一种从单一起始原料不对称合成2-取代的吡咯烷的对映异构体的新的通用方法。的(还原性环化小号小号)-γ -氯ñ -叔-butanesulfinyl酮亚胺与LiBHEt 3在THF中,在-78至23℃,得到(小号小号,- [R )- ñ -叔在优秀-butanesulfinyl -2-取代的吡咯烷收率(88-98%),非对映选择性高(99:1)。通过选择还原剂可以有效地控制非对映选择性。因此,(S S,S只需将还原剂从LiBHEt 3切换到DIBAL-H / LiHMDS,即可以高产率(87-98%)和高非对映选择性(1:99)合成)-2-取代的吡咯烷。的脱保护ñ -叔在二恶烷用4N的HCl -butanesulfinyl -2-取代的吡咯烷和MeOH,得到2-取代的吡咯烷的对映异构体对应于定量收率。发现该方法对于包括芳族,杂芳族和脂族取代基的多种底物是有效的。还说明了该方法扩展到2-取