scholarly journals Recent applications of chiral calixarenes in asymmetric catalysis

2018 ◽  
Vol 14 ◽  
pp. 1389-1412 ◽  
Author(s):  
Mustafa Durmaz ◽  
Erkan Halay ◽  
Selahattin Bozkurt
Keyword(s):  
Asymmetric Catalysis ◽  
Recent Progress ◽  
Three Dimensional ◽  
Asymmetric Syntheses

The use of calixarenes in asymmetric catalysis is receiving increasing attention due to their tunable three-dimensional molecular platforms along with their easy syntheses and versatile modification at the upper and lower rims. This review summarizes the recent progress of synthesis and use of chiral calixarenes in asymmetric syntheses which emerged later than 2010.

scholarly journals Quantum chaos for point scatterers on flat tori

2014 ◽  
Vol 372 (2007) ◽  
pp. 20120509 ◽  
Author(s):  
Henrik Ueberschär
Keyword(s):  
Wave Function ◽  
Strong Coupling ◽  
Quantum Chaos ◽  
Recent Progress ◽  
Three Dimensional ◽  
Point Scatterer ◽  
Open Problems ◽  
Survey Article ◽  
Delta Potential ◽  
Flat Tori

This survey article deals with a delta potential—also known as a point scatterer—on flat two- and three-dimensional tori. We introduce the main conjectures regarding the spectral and wave function statistics of this model in the so-called weak and strong coupling regimes. We report on recent progress as well as a number of open problems in this field.

Recent progress in Lewis acid-Lewis base bifunctional asymmetric catalysis

2005 ◽  
Vol 77 (12) ◽  
pp. 2047-2052 ◽  
Author(s):  
Motomu Kanai ◽  
Nobuki Kato ◽  
Eiko Ichikawa ◽  
Masakatsu Shibasaki
Keyword(s):  
Asymmetric Catalysis ◽  
Lewis Acid ◽  
Recent Progress ◽  
Lewis Base ◽  
Pyridine Derivatives ◽  
Asymmetric Catalysts ◽  
Strecker Reaction

Two enantioselective cyanation reactions, the Strecker reaction of ketoimines and the Reissert reaction of pyridine derivatives, promoted by Lewis acid-Lewis base bifunctional asymmetric catalysts are described.

Three-dimensional porous carbon materials and their composites as electrodes for electrochemical energy storage systems

2019 ◽  
Vol 3 (11) ◽  
pp. 2221-2245 ◽  
Author(s):  
Xiaoyang Deng ◽  
Jiajun Li ◽  
Liying Ma ◽  
Junwei Sha ◽  
Naiqin Zhao
Keyword(s):  
Energy Storage ◽  
Porous Carbon ◽  
Recent Progress ◽  
Carbon Materials ◽  
Storage Systems ◽  
Three Dimensional ◽  
Electrochemical Energy Storage ◽  
Energy Storage Systems ◽  
Porous Carbon Materials ◽  
Electrochemical Energy

This review describes the recent progress of 3D porous carbon materials and their composites as electrodes for electrochemical energy storage systems.

Recent Progress in Asymmetric Catalysis with Chiral Metal-Organic Frameworks

2020 ◽  
Vol 984 ◽  
pp. 195-204
Author(s):  
Meng Xi Zhang
Keyword(s):  
Asymmetric Catalysis ◽  
Active Sites ◽  
Recent Progress ◽  
Metal Organic Frameworks ◽  
Future Research ◽  
Asymmetric Catalysts ◽  
The Future ◽  
Metal Organic ◽  
Specific Reactions

Chiral metal-organic frameworks (CMOFs) have shown great promises in the applications of asymmetric catalysis with highly enantioselective. Herein, we briefly overview recent processes of MOF-based asymmetric catalysts based on a classification of reaction types. And we mainly focus on the structures and compositions of the active sites in these catalysts and their performances in specific reactions. In addition, some of their important unique features are critically emphasized alongside. Challenges of the future research are discussed also at the end of this review.

Molecular tectonics — Use of urethanes and ureas derived from tetraphenylmethane and tetraphenylsilane to build porous chiral hydrogen-bonded networks

2004 ◽  
Vol 82 (2) ◽  
pp. 386-398 ◽  
Author(s):  
Dominic Laliberté ◽  
Thierry Maris ◽  
James D Wuest
Keyword(s):  
Hydrogen Bonding ◽  
Asymmetric Catalysis ◽  
Crystal Engineering ◽  
Three Dimensional ◽  
Enantiomerically Pure ◽  
X Ray ◽  
Molecular Tectonics ◽  
X Ray Crystallography ◽  
Open Networks ◽  
Hydrogen Bonded

Tetraphenylmethane, tetraphenylsilane, and simple derivatives with substituents that do not engage in hydrogen bonding typically crystallize as close-packed structures with essentially no space available for the inclusion of guests. In contrast, derivatives with hydrogen-bonding groups are known to favor the formation of open networks that include significant amounts of guests. To explore this phenomenon, we synthesized six new derivatives 5a–5e and 6a of tetraphenylmethane and tetraphenylsilane with urethane and urea groups at the para positions, crystallized the compounds, and determined their structures by X-ray crystallography. As expected, all six compounds crystallize to form porous three-dimensional hydrogen-bonded networks. In the case of tetraurea 5e, 66% of the volume of the crystals is accessible to guests, and guests can be exchanged in single crystals without loss of crystallinity. Of special note are: (i) the use of tetrakis(4-isocyanatophenyl)methane (1f) as a precursor for making enantiomerically pure tetraurethanes and tetraureas, including compounds 5b, 5c; and (ii) their subsequent crystallization to give porous chiral hydrogen-bonded networks. Such materials promise to include chiral guests enantioselectively and to be useful in the separation of racemates, asymmetric catalysis, and other applications.Key words: crystal engineering, molecular tectonics, hydrogen bonding, networks, porosity, urethanes, ureas, tetraphenylmethane, tetraphenylsilane.

Simple sulfur–olefins as new promising chiral ligands for asymmetric catalysis

2014 ◽  
Vol 50 (29) ◽  
pp. 3771-3782 ◽  
Author(s):  
Yi Li ◽  
Ming-Hua Xu
Keyword(s):  
Asymmetric Catalysis ◽  
Recent Progress ◽  
Chiral Ligands ◽  
Catalytic Processes ◽  
Sulfur Containing

Recent progress on exploring sulfur-containing hybrid olefins as new elegant ligands for enantioselective catalytic processes is surveyed.

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