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
AgOAc catalyzed asymmetric [3+2] cycloaddition of azomethine ylides with chiral ferrocene derived P,S ligands
作者:Wei Zeng、Yong-Gui Zhou
DOI:10.1016/j.tetlet.2007.04.101
日期:2007.6
Ferrocene derived P,S-heterodonor ligands were effectively used in AgOAc catalyzed asymmetriccycloaddition of azomethineylides. The roles of planar chirality and electronic properties of the phosphorous substituents have been examined, and up to 93% ee was obtained.
Hydrogen-Bonding Directed Reversal of Enantioselectivity
作者:Wei Zeng、Guo-Ying Chen、Yong-Gui Zhou、Yu-Xue Li
DOI:10.1021/ja067346f
日期:2007.1.1
successful stereochemical reversal was achieved in AgOAc catalyzed [3+2] cycloaddition by the formation of hydrogen bonding between ligand and reactant. This strategy provides an efficient and convenient route to prepare both enantiomers of a chiral compound. DFT studies proposed a reasonable mechanism of the reversal of the enantioselectivity; hydrogen bonding changed the transition state. The strategy
Highly Enantioselective Ag(I)-Catalyzed [3 + 2] Cycloaddition of Azomethine Ylides
作者:James M. Longmire、Bin Wang、Xumu Zhang
DOI:10.1021/ja025969x
日期:2002.11.1
A highly reactive Ag(I)-catalyzed [3 + 2] cycloaddition of azomethineylides is founded using AgOAc as the catalytic precursor and phosphines as ligands. Using a new bis-ferrocenyl amide phosphine (FAP) as the ligand, we found that high enantioselectivities (up to 97% ee) have been achieved in the [3 + 2] cycloaddition of azomethineylides. Up to four stereogenic centers can be established in this
A new chiral phosphine oxide ligand for enantioselective 1,3-dipolar cycloaddition reactions of azomethine ylides
作者:Serap Eröksüz、Özdemir Dogan、Philip P. Garner
DOI:10.1016/j.tetasy.2010.10.002
日期:2010.10
A new set of phosphorus-containing chiral ligands has been synthesized and used with silver(I) for the catalytic asymmetric 1 3-dipolar cycloaddition reaction of azomethine ylides One of these ligands (POFAM6) was found to produce an effective catalyst for the asymmetric 1 3 dipolar cycloaddition reaction of azomethine ylides with electron deficient dipolarophiles to form pyrrolidines in up to 97% yield and 89% (C) 2010 Elsevier Ltd All rights reserved