Exploiting Nanospace for Asymmetric Catalysis: Confinement of Immobilized, Single-Site Chiral Catalysts Enhances Enantioselectivity

2008 ◽  
Vol 41 (6) ◽  
pp. 708-720 ◽  
Author(s):  
John Meurig Thomas ◽  
Robert Raja
Keyword(s):  
Asymmetric Catalysis ◽  
Single Site ◽  
Chiral Catalysts

Mesoporous SBA-15-supported chiral catalysts: preparation, characterization and asymmetric catalysis

2009 ◽  
Vol 20 (2) ◽  
pp. 240-246 ◽  
Author(s):  
Guohua Liu ◽  
Mouming Liu ◽  
Yunqiang Sun ◽  
Jianyao Wang ◽  
Chuanshou Sun ◽  
...  
Keyword(s):  
Asymmetric Catalysis ◽  
Chiral Catalysts ◽  
Catalysts Preparation

scholarly journals Kinetic Insights into Cyanosilylation of Aldehydes Catalyzed by a Covalently Bridged Dinuclear (Salen)titanium Complex

2020 ◽  
Author(s):  
Zhipeng Zhang ◽  
Zheng Wang ◽  
Kuiling Ding
Keyword(s):  
Asymmetric Catalysis ◽  
Catalytic System ◽  
Catalytic Mechanism ◽  
Organic Reactions ◽  
Kinetic Investigation ◽  
Chiral Catalysts ◽  
Titanium Complex ◽  
Trimethylsilyl Cyanide ◽  
First Order ◽  
Dual Activation

Enantioselective addition of trimethylsilyl cyanide (TMSCN) to aldehydes is one of the most extensively studied organic reactions in asymmetric catalysis. Herein, we report our intensive kinetic investigation on the asymmetric addition of TMSCN to benzaldehyde, catalyzed by a covalently bridged dinuclear (salen)titanium complex <b>2</b>, which has been one of the most efficient artificial chiral catalysts reported so far for this reaction. It was found that the method of initial rates for kinetic investigation is not appropriate in this case because of the presence of a significant <a></a><a>incubation </a>period in the catalysis, while the method of progress rates proved to be more reliable and efficient for judging the kinetic orders of this catalytic system. The kinetic results revealed that <a>the reaction follows first order with respect to the catalyst</a> and is nearly independent of concentrations of both benzaldehyde and TMSCN<a>. A detailed catalytic mechanism for cyanosilylation of benzaldehyde in the presence of <b>2</b> was proposed, wherein the key active dinuclear species works in a cooperative manner for dual activation of both reactants.</a>

scholarly journals Chiral catalysts derived from biomass: design, synthesis and applications in asymmetric catalysis

2019 ◽  
Vol 57 (6) ◽  
pp. 670-680
Author(s):  
Thi Thuy Duong Ngo ◽  
Khanh Duy Huynh ◽  
Houssein Ibrahim ◽  
Thi Huong Nguyen ◽  
Chloée Bournaud ◽  
...  
Keyword(s):  
Asymmetric Catalysis ◽  
Chiral Catalysts ◽  
Design Synthesis

scholarly journals 1H-Imidazol-4(5H)-ones and thiazol-4(5H)-ones as emerging pronucleophiles in asymmetric catalysis

2016 ◽  
Vol 12 ◽  
pp. 918-936 ◽  
Author(s):  
Antonia Mielgo ◽  
Claudio Palomo
Keyword(s):  
Asymmetric Catalysis ◽  
Asymmetric Reactions ◽  
Chiral Catalysts ◽  
Catalytic Asymmetric ◽  
Catalytic Asymmetric Reactions

Asymmetric catalysis represents a very powerful tool for the synthesis of enantiopure compounds. In this context the main focus has been directed not only to the search for new efficient chiral catalysts, but also to the development of efficient pronucleophiles. This review highlights the utility and first examples of 1H-imidazol-4(5H)-ones and thiazol-4(5H)-ones as pronucleophiles in catalytic asymmetric reactions.

Supported ionic liquid asymmetric catalysis. A new method for chiral catalysts recycling. The case of proline-catalyzed aldol reaction

2004 ◽  
Vol 45 (32) ◽  
pp. 6113-6116 ◽  
Author(s):  
Michelangelo Gruttadauria ◽  
Serena Riela ◽  
Paolo Lo Meo ◽  
Francesca D'Anna ◽  
Renato Noto
Keyword(s):  
Ionic Liquid ◽  
Asymmetric Catalysis ◽  
Aldol Reaction ◽  
New Method ◽  
Chiral Catalysts ◽  
Supported Ionic Liquid

Development of homogeneous and heterogeneous asymmetric catalysts for practical enantioselective reactions

2006 ◽  
Vol 78 (2) ◽  
pp. 293-301 ◽  
Author(s):  
Kuiling Ding
Keyword(s):  
Metal Ions ◽  
Asymmetric Catalysis ◽  
Asymmetric Hydrogenation ◽  
Combinatorial Approach ◽  
Chiral Catalysts ◽  
Asymmetric Catalysts ◽  
Highly Efficient ◽  
Enantioselective Reactions ◽  
New Strategy ◽  
Hydrogenation Reactions

Two strategies for the development of practical asymmetric catalysis have been discussed in this article. The first part of this article focuses on the design and screening of highly efficient and enantioselective chiral catalysts for asymmetric hydrogenation reactions employing combinatorial approach. The second part presents a conceptually new strategy (i.e., "self-supporting" approach) for the immobilization of homogeneous catalysts through assembly of chiral multitopic ligands and metal ions without using any support. The success of this strategy will be exemplified in heterogeneous asymmetric carbonyl-ene, sulfoxidation, and epoxidation, as well as in asymmetric hydrogenation reactions.

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