C-H Functionalization of Amino Alcohols by Osmium Tetroxide/NMO or TPAP/NMO: Protecting Group-Free Synthesis of Indolizidines (-)-223AB and 3-<i>epi</i>
-(-)-223AB
作者:Wei-Lun Chen、Lee-Ya Wang、Yu-Jang Li
DOI:10.1002/ejoc.201901494
日期:2020.1.9
perruthenate, with NMO provide N,O‐acetal moieties by trapping the resulting iminium ion with the alcohol. These two transformations were demonstrated in the protecting group free synthesis of indolizidines (–)‐223AB and 3‐epi‐(–)‐223AB, compounds found in dart‐frog poison.
quaternary centers were synthesized in moderate to good yields by treatment of various hexahydro-3,4-dioxa-8a-aza-as-indacen-2-ones with m-CPBA under basic conditions through a tandem Cope elimination/1,3-dipolar cycloadditionreaction sequence, followed by N-O cleavage and lactam ring cyclization.
Construction of stereogenic center beta to the N-Pyrrolidinyl moiety via diastereoselective reactions of tricyclic lactones and the synthesis of (−)-Indolizidine 195G
作者:Rou-Jie Huang、Ching-Zong Luo、Wei-Kai Liao、Hsiang-Yu Chuang、Yu-Jang Li
DOI:10.1016/j.tet.2024.134024
日期:2024.6
The Enolates of hexahydro-3,4-dioxa-8a-aza--indacen-2-ones can react with electrophiles in a substrate-controlled fashion to create a new stereogenic center positioned beta to the N-pyrrolidinyl moiety. Preferential diastereoselective reactions predominantly proceeded from the convex face of the enolates, yielding stereospecific alkylated or halo-substituted products with high yields and exceptional