Origin of Stereodivergence in Cooperative Asymmetric Catalysis with Simultaneous Involvement of Two Chiral Catalysts

2015 ◽  
Vol 137 (50) ◽  
pp. 15712-15722 ◽  
Author(s):  
Bangaru Bhaskararao ◽  
Raghavan B. Sunoj
2009 ◽  
Vol 20 (2) ◽  
pp. 240-246 ◽  
Author(s):  
Guohua Liu ◽  
Mouming Liu ◽  
Yunqiang Sun ◽  
Jianyao Wang ◽  
Chuanshou Sun ◽  
...  

2020 ◽  
Author(s):  
Zhipeng Zhang ◽  
Zheng Wang ◽  
Kuiling Ding

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>


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

2016 ◽  
Vol 12 ◽  
pp. 918-936 ◽  
Author(s):  
Antonia Mielgo ◽  
Claudio Palomo

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.


2004 ◽  
Vol 45 (32) ◽  
pp. 6113-6116 ◽  
Author(s):  
Michelangelo Gruttadauria ◽  
Serena Riela ◽  
Paolo Lo Meo ◽  
Francesca D'Anna ◽  
Renato Noto

2006 ◽  
Vol 78 (2) ◽  
pp. 293-301 ◽  
Author(s):  
Kuiling Ding

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.


2006 ◽  
Vol 118 (33) ◽  
pp. 5628-5631 ◽  
Author(s):  
James C. Ianni ◽  
Venkatachalam Annamalai ◽  
Puay-Wah Phuan ◽  
Manoranjan Panda ◽  
Marisa C. Kozlowski

Sign in / Sign up

Export Citation Format

Share Document