Synthesis of Chiral Biphenol-Based Diphosphonite Ligands and Their Application in Palladium-Catalyzed Intermolecular Asymmetric Allylic Amination Reactions
作者:Ce Shi、Chih-Wei Chien、Iwao Ojima
DOI:10.1002/asia.201000697
日期:2011.2.1
library of new 2,2′‐bis(diphenylphosphinoyloxy)‐1,1′‐binaphthyl (binapo)‐type chiral diphosphonite ligands was designed and synthesized based on chiral 3,3′,5,5′,6,6′‐hexasubstituted biphenols. These bop ligands have exhibited excellent efficiency in a palladium‐catalyzed intermolecular allylic amination reaction, which provides a key intermediate for the total synthesis of Strychnosindole alkaloids
Pd-Catalyzed Asymmetric Allylic Etherification Using Chiral Biphenol-Based Diphosphinite Ligands and Its Application for The Formal Total Synthesis of (−)-Galanthamine
作者:Yang Zang、Iwao Ojima
DOI:10.1021/jo400355j
日期:2013.4.19
A library of novelchiral biphenol-based diphosphinite (BOP) ligands was designed and created. These BOP ligands were applied to a Pd-catalyzed intermolecular allylic etherification reaction, which provided a key intermediate for the formaltotalsynthesis of (−)-galanthamine with 97% ee in 97% yield.
effective leavinggroup in palladium-catalyzed allylic substitution. When the reaction of an equimolar amount of allyl methyl carbonate and allyl vinyl carbonate with dimethyl malonate was carried out in the presence of a palladium catalyst, allyl vinyl carbonate reacted with the nucleophile, and most of allyl methyl carbonate remained unchanged. In the reaction of a compound having allyl methyl carbonate
Pd-catalyzed asymmetric allylic amination with BOP ligands and its applications to the synthesis of fused polycyclic alkaloids
作者:Yang Zang、Iwao Ojima
DOI:10.1016/j.tetlet.2015.01.047
日期:2015.6
Pd-catalyzed asymmetric allylic amination reaction of piperonylamides and a 2-siloxymethylcyclohexenyl carbonate, using chiral biphenol-based diphosphinite (BOP) ligands gave the corresponding cyclohexenylpiperonylamides in excellent yield and enantiopurity (93-95% ee). These amides were applied to the synthesis of fused polycyclic alkaloids in a short sequence of steps. (C) 2015 Elsevier Ltd. All rights reserved.