Bifunctional AgOAc-Catalyzed Asymmetric [3 + 2] Cycloaddition of Azomethine Ylides
作者:Wei Zeng、Yong-Gui Zhou
DOI:10.1021/ol0520370
日期:2005.10.1
[reaction: see text] A bifunctional AgOAc-catalyzed asymmetriccycloaddition of azomethineylides with electronic-deficient alkenes was developed using ferrocenyloxazoline-derived N,P ligands. The reactive metal-bound azomethineylide dipole is formed by the deprotonation with acetate, and extra base is not necessary. The reactions proceed with high enantioselectivity. This method provides an efficient
A novel Fe(II)/diaryl prolinol catalyzed asymmetric 1,3-dipolar cycloaddition of azomethine ylides with alkenes
作者:Haisheng Wu、Bo Wang、Hongqiang Liu、Lei Wang
DOI:10.1016/j.tet.2010.11.091
日期:2011.2
A novel Fe(II)/diaryl prolinol catalyzed asymmetric1,3-dipolarcycloaddition of azomethineylides with alkenes has been developed. In the presence of FeCl2 (10 mol %) and α,α-bis(3,5-bistrifluoromethylphenyl)prolinol L1 (10 mol %), [3+2] cycloaddition of azomethineylides with electronic-deficient olefins underwent smoothly in CH3CN at room temperature to generate the desired endo-adducts in moderate
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