ChemInform Abstract: (1R,2R)-Bis[(S)-prolinamido]cyclohexane Modified with Ionic Groups: The First C2-Symmetric Immobilized Organocatalyst for Asymmetric Aldol Reactions in Aqueous Media.

ChemInform ◽  
2012 ◽  
Vol 43 (12) ◽  
pp. no-no
Author(s):  
Sergei V. Kochetkov ◽  
Alexandr S. Kucherenko ◽  
Sergei G. Zlotin
Keyword(s):  
Aqueous Media ◽  
Aldol Reactions ◽  
Asymmetric Aldol ◽  
Ionic Groups

scholarly journals Catalytic Asymmetric Aldol Reactions in Aqueous Media Using Chiral Bis-pyridino-18-crown-6—Rare Earth Metal Triflate Complexes.

ChemInform ◽  
2003 ◽  
Vol 34 (28) ◽  
Author(s):  
Tomoaki Hamada ◽  
Kei Manabe ◽  
Shunpei Ishikawa ◽  
Satoshi Nagayama ◽  
Motoo Shiro ◽  
...  
Keyword(s):  
Rare Earth ◽  
Rare Earth Metal ◽  
Aqueous Media ◽  
Earth Metal ◽  
Aldol Reactions ◽  
Asymmetric Aldol ◽  
Catalytic Asymmetric

scholarly journals Catalytic Asymmetric Aldol Reactions in Aqueous Media

2003 ◽  
Vol 61 (5) ◽  
pp. 445-453 ◽  
Author(s):  
Tomoaki Hamada ◽  
Kei Manabe ◽  
Shu Kobayashi
Keyword(s):  
Aqueous Media ◽  
Aldol Reactions ◽  
Asymmetric Aldol ◽  
Catalytic Asymmetric

Lanthanide Trifluoromethanesulfonate-Catalyzed Asymmetric Aldol Reactions in Aqueous Media

2001 ◽  
Vol 3 (2) ◽  
pp. 165-167 ◽  
Author(s):  
Shū Kobayashi ◽  
Tomoaki Hamada ◽  
Satoshi Nagayama ◽  
Kei Manabe
Keyword(s):  
Aqueous Media ◽  
Aldol Reactions ◽  
Asymmetric Aldol

Catalytic Asymmetric Aldol Reactions in Aqueous Media Using Chiral Bis-pyridino-18-crown-6−Rare Earth Metal Triflate Complexes

2003 ◽  
Vol 125 (10) ◽  
pp. 2989-2996 ◽  
Author(s):  
Tomoaki Hamada ◽  
Kei Manabe ◽  
Shunpei Ishikawa ◽  
Satoshi Nagayama ◽  
Motoo Shiro ◽  
...  
Keyword(s):  
Rare Earth ◽  
Rare Earth Metal ◽  
Aqueous Media ◽  
Earth Metal ◽  
Aldol Reactions ◽  
Asymmetric Aldol ◽  
Catalytic Asymmetric

New Mechanistic Approach in the Enamine-Based Asymmetric Organocatalysis

2021 ◽  
Author(s):  
András A. Gurka
Keyword(s):  
Water Molecule ◽  
Transition State ◽  
Aqueous Media ◽  
Initial Step ◽  
Aldol Reactions ◽  
Asymmetric Aldol ◽  
Mechanistic Approach ◽  
Asymmetric Organocatalysis ◽  
Organocatalytic Reactions ◽  
Proline Derivatives

Abstract During the course of my research in asymmetric organocatalysis the inversion of enantioselectivity was observed in the asymmetric aldol reactions of acetone with different aldehydes catalyzed by amphiphilic proline derivatives in aqueous media varying only achiral components. It was not possible to explain the explored dual stereocontrol with the existing models, therefore I proposed a new mechanism for asymmetric aldol reactions catalyzed by l-amino acid derivatives in aqueous media and explained the explored phenomenon of inversion of enantioselectivity with different structures of micelle-stabilized transition state described as a metal-free version of the Zimmermann-Traxler model with explicit participation of a water molecule. Contrary to the existing models, according to the proposed mechanism the formation of new bonds proceeds directly in the transition state stabilized by a water molecule without the additional step of product iminium ion hydrolysis. The proposed mechanism has universal character, it is consistent with experimental results and general theoretical conceptions and it is applicable to all enamine-based asymmetric organocatalytic reactions carried out not only in aqueous, but in organic media as well, because the initial step of catalytic cycle, which involves the formation of an enamine from the carbonyl compound and proline (derivative), liberates one water molecule.

2-Hydroxy-3-[(S)-prolinamido]pinanes as novel bifunctional organocatalysts for asymmetric aldol reactions in aqueous media

2011 ◽  
Vol 22 (12) ◽  
pp. 1320-1324 ◽  
Author(s):  
Dmitry E. Siyutkin ◽  
Alexander S. Kucherenko ◽  
Larisa L. Frolova ◽  
Alexander V. Kuchin ◽  
Sergei G. Zlotin
Keyword(s):  
Aqueous Media ◽  
Aldol Reactions ◽  
Asymmetric Aldol

ChemInform Abstract: Highly Efficient Direct Asymmetric Aldol Reactions Catalyzed by a Prolinethioamide Derivative in Aqueous Media.

ChemInform ◽  
2011 ◽  
Vol 42 (9) ◽  
pp. no-no
Author(s):  
Bing Wang ◽  
Xin-wang Liu ◽  
Ling-yan Liu ◽  
Wei-xing Chang ◽  
Jing Li
Keyword(s):  
Aqueous Media ◽  
Aldol Reactions ◽  
Asymmetric Aldol ◽  
Highly Efficient
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