Reaction Discovery Employing Macrocycles: Transannular Cyclizations of Macrocyclic Bis-lactams
作者:Chong Han、Sathish Rangarajan、Alicia C Voukides、Aaron B. Beeler、Richard Johnson、John A. Porco
DOI:10.1021/ol802729f
日期:2009.1.15
Macrocyclic bis-lactams have been synthesized by cyclodimerization of homoallylic amino esters employing a Zr(IV)-catalyzed ester-amide exchange protocol. Base-mediated transannular cyclizations have been identified to access both bicyclic [5-11] and tricyclic [5-8-5] frameworks in good yield and diastereoselectivity. Preliminary mechanistic studies support an olefin isomerization−intramolecular conjugate
大环双内酰胺是通过高烯丙基氨基酯的环二聚反应合成的,采用 Zr(IV) 催化的酯-酰胺交换方案。已确定碱基介导的环环化以良好的产率和非对映选择性访问双环 [5-11] 和三环 [5-8-5] 框架。初步机理研究支持烯烃异构化 - 分子内共轭加成途径。