Synthesis of new chiral ferrocenyl P,N-ligands with a benzoxazole ring and their application in Ag-catalyzed asymmetric [3+2] cycloaddition
摘要:
New chiral ferrocenyl P,N-ligands with a benzoxazole ring as the N-donor group have been synthesized from 2-aminophenol through a three-step transformation and successfully employed in the Ag-catalyzed asymmetric [3+2] cycloaddition of azomethine ylides with electron-deficient alkenes. High diastereoselectivities, excellent enantioselectivities, and good yields have been achieved for a variety of substrates, demonstrating the potential of these new P,N-ligands in asymmetric catalysis. (C) 2013 Elsevier Ltd. All rights reserved.
DBU-Catalyzed [3+3] and [3+2] Annulation Reactions of Azomethine Ylides with α-Diazocarbonyls as<i>N</i>-Terminal Electrophiles: Modular, Atom-Economical Access to 1,2,4-Triazine and 1,2,4-Triazole Derivatives
DBU‐catalyzed [3+3] and [3+2] cyclization reactions of azomethine ylides with α‐diazocarbonyls as N‐terminal electrophiles have been developed. These reactions involve a sequential intermolecular nucleophilic addition/intramolecularcyclization/oxidation procedure. By the assembly of readily available starting materials, these transformations offer novel, highlyefficient one‐pot syntheses of various
Zn(ii)-catalyzed asymmetric [3 + 2] cycloaddition of acyclic enones with azomethine ylides
作者:Sundaravel Vivek Kumar、Jeremiah Olusegun、Patrick J. Guiry
DOI:10.1039/d4ob00854e
日期:——
The Zn(II)/UCD-Imphanol-catalyzed highly endo-selective [3 + 2] asymmetriccycloaddition of acyclic enones and azomethineylides has been developed. Moderate to high yields (up to 94%) with excellent endo/exo selectivities (99 : 1) and enantioselectivities up to 96.5 : 3.5 er were obtained.
开发了 Zn( II )/UCD-Imphanol 催化的无环烯酮和偶氮甲碱叶立德的高度内选择性 [3 + 2] 不对称环加成反应。获得了中等到高产率(高达 94%),具有出色的内切/外切选择性(99:1)和高达 96.5:3.5 er 的对映选择性。