Electronic Effects in Asymmetric Catalysis:  Structural Studies of Precatalysts and Intermediates in Rh-Catalyzed Hydrogenation of Dimethyl Itaconate and Acetamidocinnamic Acid Derivatives UsingC2-Symmetric Diarylphosphinite Ligands

1999 ◽  
Vol 64 (10) ◽  
pp. 3429-3447 ◽  
Author(s):  
T. V. RajanBabu ◽  
Branko Radetich ◽  
Kamfia K. You ◽  
Timothy A. Ayers ◽  
Albert L. Casalnuovo ◽  
...  
Keyword(s):  
Asymmetric Catalysis ◽  
Structural Studies ◽  
Electronic Effects ◽  
Dimethyl Itaconate

Homogeneous asymmetric catalysis: structural studies of catalytic intermediates using extended x-ray absorption fine structure

1981 ◽  
Vol 103 (11) ◽  
pp. 3235-3237 ◽  
Author(s):  
B. Ray Stults ◽  
Robert Mark Friedman ◽  
Karl Koenig ◽  
William Knowles ◽  
Robert B. Greegor ◽  
...  
Keyword(s):  
Fine Structure ◽  
Asymmetric Catalysis ◽  
Structural Studies ◽  
X Ray ◽  
Absorption Fine ◽  
Catalytic Intermediates ◽  
X Ray Absorption

Synthesis, characterization, and application in asymmetric catalysis of dendrimers containing chiral ferrocenyl diphosphines

2001 ◽  
Vol 79 (11) ◽  
pp. 1762-1774 ◽  
Author(s):  
Christoph Köllner ◽  
Antonio Togni
Keyword(s):  
Asymmetric Catalysis ◽  
Isophthalic Acid ◽  
Tricarboxylic Acid ◽  
Catalytic Reactions ◽  
Allylic Substitution ◽  
Asymmetric Catalytic ◽  
Ferrocenyl Ligands ◽  
The One ◽  
Parent Ligand ◽  
Dimethyl Itaconate

Starting from the functionalized Josiphos derivatives (R)-1-[(S)-2-(diphenylphosphino)-1'-(dimethyl-3''-aminopropylsilyl)-ferrocenyl]ethyldicyclohexylphosphine ((R)-(S)-3), (R)-1-[(S)-2-(diphenylphosphino)-1'-(hydroxy methyl) ferrocenyl]ethyldicyclohexylphosphine ((R)-(S)-4), and (R)-1-[(S)-2-(diphenylphosphino)-1'-(3''-hydroxy propyl)ferrocenyl]ethyldicyclohexylphosphine ((R)-(S)-5), a series of dendrimers containing up to sixteen ferrocenyl diphosphine units were prepared. Dendrimer cores are based on benzene 1,3,5-tricarboxylic acid and 1,3,5,7-adaman tanetetracarboxylic acid, with 5-substituted isophthalic acid derivatives constituting the branching units. The dendrimers have been used in three different asymmetric catalytic reactions: Rh-catalyzed hydrogenation of dimethyl itaconate, Pd-catalyzed allylic substitution, and Rh-catalyzed hydroboration of styrene with catecholborane. In all three reactions the selectivity obtained with the dendrimers was very similar to the one obtained with the parent ligand Josiphos.Key words: dendrimer, asymmetric catalysis, ferrocenyl ligands, hydrogenation.

scholarly journals Chiral covalent organic frameworks: design, synthesis and property

2020 ◽  
Author(s):  
X Han ◽  
C Yuan ◽  
B Hou ◽  
Lujia Liu ◽  
H Li ◽  
...  
Keyword(s):  
Porous Materials ◽  
Asymmetric Catalysis ◽  
Chiral Recognition ◽  
Building Blocks ◽  
Enantioselective Separation ◽  
Structural Studies ◽  
Covalent Organic Frameworks ◽  
Covalent Bonds ◽  
Design Synthesis ◽  
Potential Applications

Covalent organic frameworks (COFs) are constructed using reticular chemistry with the building blocks being connected via covalent bonds and have emerged as a new series of porous materials for multitudinous applications. Most COFs reported to date are achiral, and only a small fraction of COFs with chiral nature are reported. This review covers the recent advances in the field of chiral COFs (CCOFs), including their design principles and synthetic strategies, structural studies, and potential applications in asymmetric catalysis, enantioselective separation, and chiral recognition. Finally, we illustrate the remaining challenges and future opportunities in this field.

scholarly journals Chiral covalent organic frameworks: design, synthesis and property

2020 ◽  
Author(s):  
X Han ◽  
C Yuan ◽  
B Hou ◽  
Lujia Liu ◽  
H Li ◽  
...  
Keyword(s):  
Porous Materials ◽  
Asymmetric Catalysis ◽  
Chiral Recognition ◽  
Building Blocks ◽  
Enantioselective Separation ◽  
Structural Studies ◽  
Covalent Organic Frameworks ◽  
Covalent Bonds ◽  
Design Synthesis ◽  
Potential Applications

Covalent organic frameworks (COFs) are constructed using reticular chemistry with the building blocks being connected via covalent bonds and have emerged as a new series of porous materials for multitudinous applications. Most COFs reported to date are achiral, and only a small fraction of COFs with chiral nature are reported. This review covers the recent advances in the field of chiral COFs (CCOFs), including their design principles and synthetic strategies, structural studies, and potential applications in asymmetric catalysis, enantioselective separation, and chiral recognition. Finally, we illustrate the remaining challenges and future opportunities in this field.

Molecular structure and substituent electronic effects in 10-arylidenanthrones-9

2000 ◽  
Vol 215 (5) ◽  
Author(s):  
O.V. Shishkin ◽  
A.Yu. Kovalevsky ◽  
M. Yu. Antipin ◽  
Z.N. Tarakhno
Keyword(s):  
Gas Phase ◽  
Phenyl Group ◽  
Conformational Flexibility ◽  
Am1 Method ◽  
Equilibrium Geometry ◽  
Boat Conformation ◽  
Structural Studies ◽  
Electronic Effects ◽  
X Ray ◽  
Derivatives Of

X-ray structural studies of derivatives of 10-arylidenanthrone-9 containing π-electron donating and withdrawing substituents within arylidene fragment have been carried out. In the crystal the molecules are strongly disflattened with the central dihydrocycles adopting an asymmetric boat conformation. This geometry of the molecules is a result of unfavourable non-valence interactions between atoms at the C=C bond and the hydrogens at the peri-positions of the anthraquinone fragment. Calculations performed by the semiempirical quantum-chemical AM1 method demonstrate that in the gas phase equilibrium geometry of the molecules was similar to that in the crystal. It was shown as well that the central dihydrocycle possesses high conformational flexibility in spite of steric overcrowding in all of the compounds. Electronic effects of the substituents had significant influence only on the arylidene moiety, resulting in different rotation angles of the phenyl group around the C=C exocyclic bond and virtually no effect on the anthraquinone part of the molecules.

Substituent Electronic Effects in Chiral Ligands for Asymmetric Catalysis

ChemInform ◽  
2006 ◽  
Vol 37 (33) ◽  
Author(s):  
Susan P. Flanagan ◽  
Patrick J. Guiry
Keyword(s):  
Asymmetric Catalysis ◽  
Chiral Ligands ◽  
Electronic Effects
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