CuI–Fesulphos complexes: efficient chiral catalysts for asymmetric 1,3-dipolar cycloaddition of azomethine ylides
摘要:
The Cu-I-Fesulphos catalyst system (<= 3 mol %) shows an excellent performance in the asymmetric 1,3-dipolar cycloaddition of azomethine ylides. High to very high levels of reactivity, endo/exo selectivity, and enantioselectivity ( 69->99% ee) are generally achieved with a very wide range of azomethine ylides and dipolarophiles. Based on experimental and computational studies data, a model that accounts for this high enantiocontrol is proposed. (c) 2007 Elsevier Ltd. All rights reserved.
Highly Enantioselective Asymmetric 1,3-Dipolar Cycloaddition of Azomethine Ylide Catalyzed by a Copper(I)/ClickFerrophos Complex
作者:Shin-ichi Fukuzawa、Hiroshi Oki
DOI:10.1021/ol8003996
日期:2008.5.1
A copper(I)/ClickFerrophos complexcatalyzed the asymmetric 1,3-dipolar cycloaddition reaction of methyl N-benzylideneglycinate (the source of azomethine ylides) with vinyl sulfone to give the exo-2,4,5-trisubstituted pyrrolidine in good yield with high enantioselectivity (99% ee). The complex also effectively catalyzed reactions of other dipolarophiles such as acrylates, maleate, and maleimides to
Asymmetric [3+2] Cycloaddition of Azomethine Ylides Catalyzed by Silver(I) Triflate with a Chiral Bipyrrolidine-Derived Phosphine Ligand
作者:Zhen-Jiang Xu、Chi-Ming Che、Xin Gu、Vanessa Lo
DOI:10.1055/s-0032-1316779
日期:——
bipyrrolidine-derived phosphine ligands L1 and L2 were synthesized. The ‘AgOTf + L1’ protocol catalyzes the asymmetric [3+2] cycloaddition of azomethineylides with alkenes to give highly substituted pyrrolidines in good yields (up to 90%) with moderate to high diastereoselectivities (up to >19:1 dr) and enantioselectivities (up to 76%). Two novel chiral bipyrrolidine-derived phosphine ligands L1 and L2 were synthesized
Cu II -catalysed asymmetric 1,3-dipolar cycloaddition of azomethine ylides with a chiral ferrocene-derived P,N-ligand
作者:Bilel Bdiri、Li Dai、Zhi-Ming Zhou
DOI:10.1016/j.tetlet.2017.05.044
日期:2017.6
A ferrocene-derived P,N-heterodonor ligand was effectively used in a Cu(OAc)2·H2O-catalysed asymmetric 1,3-dipolarcycloaddition of azomethine ylides with maleate derivatives, affording cycloadducts with high yields (up to 96%), diastereoselectivities (>99 dr), and enantioselectivities (up to 99% ee).