Stereoselective Multicomponent Assembly of Enantiopure Oxazolopiperidines and -azepines
作者:Nicolas Zill、Angèle Schoenfelder、Nicolas Girard、Maurizio Taddei、André Mann
DOI:10.1021/jo202455c
日期:2012.3.2
efficient diastereoselective preparation of oxazolopiperidines (4a–e) and -azepines (7a–d). The bicyclic oxazolidines were obtained from chiral N-alkenylamino alcohols via transient cyclic iminium intermediates that underwent an intramolecular cyclization from the appendant oxygen. On the basis of a series of different experimental conditions, the diastereocontrol observed during the formation of the
建立了基于加氢甲酰化的环氢羰基化(CHC)的多组分反应(MCR),以有效地对映选择性制备恶唑并哌啶(4a – e)和-azepine(7a – d)。双环的恶唑烷是从手性的N-链烯基氨基醇经短暂的环亚胺中间体得到的,该中间体从附加的氧分子内环化。根据一系列不同的实验条件,在恶唑烷类化合物形成过程中观察到的非对映异构控制最好用常见的环状亚胺中间体(A A,3-应变)诱导的立体电子效应来解释。)。该新序列适用于面向多样性的合成,从而允许从市售材料中分五个步骤制备对映体纯(S)-和(R)-可可碱。