Stereoselective Synthesis of New Chiral <i>N</i>-Tertiary Tetrasubstituted β-Enamino Ester Piperidines through an Ammonia-Catalyzed Process
作者:Sandrine Calvet-Vitale、Corinne Vanucci-Bacqué、Marie-Claude Fargeau-Bellassoued、Gérard Lhommet
DOI:10.1021/jo052490p
日期:2006.3.1
We report here two approaches for the preparation of new N-substituted β-enamino ester piperidines featuring an exocyclic tetrasubstituted double bond, based either on the direct alkylation of piperidine β-enamino esters bearing an exocyclic trisubstituted double bond or on the intramolecular cyclization of linear amino β-keto esters. The target compounds were obtained as unusual (Z)-stereoisomers
我们在这里报告两种方法,用于制备具有环外四取代双键的新的N-取代的β-烯氨基酯哌啶,基于带有环外三取代双键的哌啶β-烯胺酯的直接烷基化或基于线性的分子内环化氨基β-酮酯。以高收率获得了目标化合物,为不寻常的(Z)-立体异构体。强调了氨作为亲核试剂和碱的试剂的关键作用。产物的非对映选择性形成是基于氨加成-syn消除催化过程而合理化的。