Catalytic Asymmetric [3+2] Cycloaddition of Azomethine Ylides. Development of a Versatile Stepwise, Three-Component Reaction for Diversity-Oriented Synthesis
作者:Chuo Chen、Xiaodong Li、Stuart L. Schreiber
DOI:10.1021/ja036558z
日期:2003.8.1
We report a new catalyst system that should enhance the use of enantioselective 1,3-dipolar cycloadditions of azomethine ylides with electronic-deficient olefins in the divergent pathways of diversity-oriented synthesis (DOS). The underlying reaction is of considerable interest in DOS because its stereospecificity enables stereochemical diversification of up to four tetrahedral centers on pyrrolidine
我们报告了一种新的催化剂系统,该系统应该在多样性导向合成 (DOS) 的不同途径中增强对偶氮甲碱叶立德与缺电子烯烃的对映选择性 1,3-偶极环加成的使用。潜在的反应在 DOS 中引起了相当大的兴趣,因为它的立体定向性使吡咯烷环上多达四个四面体中心的立体化学多样化成为可能。这种新的催化剂系统扩展了偶氮甲碱叶立德环加成反应的范围和选择性,并且与用于 DOS 的单珠/单储备溶液技术平台中使用的试剂兼容。
C2-Symmetric S/C/S ligands based on N-heterocyclic carbenes: a new ligand architecture for asymmetric catalysis
作者:Javier Iglesias-Sigüenza、Abel Ros、Elena Díez、Antonio Magriz、Arcadio Vázquez、Eleuterio Álvarez、Rosario Fernández、José M. Lassaletta
DOI:10.1039/b910846g
日期:——
Neutral, C2-symmetric S/C/S ligands based on N-heterocyclic carbenes and thioether functionalities were incorporated into transition metal complexes characterised by two direct metal-stereogenic sulfur bonds. This new ligand design was applied to 1,3-dipolar cycloadditions as the first example of the use silver of carbenes in asymmetric catalysis.
Reversal of Enantioselectivity between the Copper(I)- and Silver(I)-Catalyzed 1,3-Dipolar Cycloaddition Reactions Using a Brucine-Derived Amino Alcohol Ligand
作者:Hun Young Kim、Hui-Ju Shih、William E. Knabe、Kyungsoo Oh
DOI:10.1002/anie.200903479
日期:2009.9.21
The old switcheroo: The switch in the enantioselectivity of a reaction by using a single chiral source has been achieved using different metal binding modes of the chiral aminoalcohol 1 in the presence of CuI and AgI sources. Azomethine ylides were shown to undergo highly enantio‐ and diastereoselective 1,3‐dipolar cycloadditions with substituted tert‐butyl acrylates to provide both of the enantiomerically
Readily Available Biaryl P,N Ligands for Asymmetric Catalysis
作者:Thomas F. Knöpfel、Patrick Aschwanden、Takashi Ichikawa、Takumi Watanabe、Erick M. Carreira
DOI:10.1002/anie.200461286
日期:2004.11.12
New Zinc(II)-Based Catalyst for Asymmetric Azomethine Ylide Cycloaddition Reactions
作者:Özdemir Dogan、Hasan Koyuncu、Philip Garner、Adnan Bulut、Wiley J. Youngs、Matthew Panzner
DOI:10.1021/ol061521f
日期:2006.10.1
A new chiral aziridino alcohol ligand for zinc(II)-catalyzed azomethine ylide cycloadditions is described. In the presence of this catalyst, N-arylidene glycine methyl esters react with a variety of dipolarophiles to give substituted pyrrolidines in very good to excellent chemical yields and up to 95% ee. The absolute sense of asymmetric induction appears to be dipolarophile-dependent.