Department of Chemistry, Chemistry Research Laboratory, University of Oxford, Mansfield Road, Oxford OX1 3TA, UK.
Org Lett. 2012 Jan 6;14(1):218-21. doi: 10.1021/ol203011u. Epub 2011 Dec 7.
Conjugate addition of a 50:50 pseudoenantiomeric mixture of lithium (R)-N-benzyl-N-(α-methylbenzyl)amide and lithium (S)-N-3,4-dimethoxybenzyl-N-(α-methylbenzyl)amide to a range of racemic acyclic γ-amino-α,β-unsaturated esters (derived from the corresponding α-amino acids) effects their efficient parallel kinetic resolution, allowing the preparation of enantiopure β,γ-diamino esters. The β,γ-diamino ester products of these reactions are readily converted into the corresponding substituted 4-aminopyrrolidin-2-ones via N-debenzylation and cyclization.
(R)-N-苄基-N-(α-甲基苄基)酰胺和(S)-N-(3,4-二甲氧基苄基)-N-(α-甲基苄基)酰胺的锂盐以 50:50 的外消旋伪对映体混合物与一系列外消旋非环 γ-氨基-α,β-不饱和酯(由相应的α-氨基酸衍生而来)进行共轭加成,可对其进行高效的平行动力学拆分,从而得到对映纯的β,γ-二氨基酯。这些反应的β,γ-二氨基酯产物通过脱苄基和环化很容易转化为相应的取代 4-氨基吡咯烷-2-酮。