Synthesis of the Smallest Axially Chiral Molecule by Asymmetric Carbon-Fluorine Bond Activation

2012 ◽  
Vol 51 (9) ◽  
pp. 2218-2220 ◽  
Author(s):  
Moritz F. Kuehnel ◽  
Tobias Schlöder ◽  
Sebastian Riedel ◽  
Belén Nieto-Ortega ◽  
Francisco J. Ramírez ◽  
...  
Keyword(s):  
Bond Activation ◽  
Chiral Molecule ◽  
Axially Chiral ◽  
Asymmetric Carbon

scholarly journals Organocatalytic asymmetric N-sulfonyl amide C-N bond activation to access axially chiral biaryl amino acids

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Guanjie Wang ◽  
Qianqian Shi ◽  
Wanyao Hu ◽  
Tao Chen ◽  
Yingying Guo ◽  
...  
Keyword(s):  
Amino Acids ◽  
Bond Activation ◽  
Axially Chiral

scholarly journals Twofold C-H Activation-Based Enantio- and Diastereoselective C-H Arylation Using Diarylacetylenes as Rare Arylating Reagents

2021 ◽  
Author(s):  
Panjie Hu ◽  
Lingheng Kong ◽  
Fen Wang ◽  
Xiaolin Zhu ◽  
Xingwei Li
Keyword(s):  
Bond Activation ◽  
Major Product ◽  
Activation Reaction ◽  
Axial Chirality ◽  
Mild Conditions ◽  
Straightforward Method ◽  
Axially Chiral

<p>C-H bond activation has been established as an attractive strategy to access axially chiral biaryls, and the most straightforward method is direct C-H arylation of arenes. However, the arylating source has been limited to several classes of reactive and bulky reagents. Reported herein is rhodium-catalyzed 1:2 coupling of diarylphosphinic amides and diarylacetylenes for enantio- and diastereoselective construction of biaryls with both central and axial chirality. This twofold C-H activation reaction stays contrast to the previously explored Miura-Satoh type 1:2 coupling of arenes and alkynes in terms of chemoselectivity and proceeded under mild conditions with the alkyne acting as a rare arylating reagent. Both C-H activation events are stereo-determining and are under catalyst control, with the 2<sup>nd</sup> C-H activation being diastereo-determining in a remote fashion. Analysis of the stereochemistries of the major and side products suggests moderated enantioselectivity of the initial C-H activation-desymmetrization process. However, the minor stereoisomeric (<i>R</i>) intermediate is consumed more readily in undesired protonolysis, eventually resulting in high enantio- and diastereoselectivity of the major product.</p>

scholarly journals Through a Glass Darkly—Some Thoughts on Symmetry and Chemistry

Symmetry ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 1891
Author(s):  
Edwin C. Constable
Keyword(s):  
Optical Properties ◽  
Carbon Atom ◽  
Chemical Structure ◽  
Final Section ◽  
Chiral Molecule ◽  
Asymmetric Carbon Atom ◽  
Different Types ◽  
Properties Of Materials ◽  
Optical Properties Of Materials ◽  
Asymmetric Carbon

This article reviews the development of concepts of chirality in chemistry. The story follows the parallel development of the optical properties of materials and the understanding of chemical structure until the two are fused in the recognition of the tetrahedral carbon atom in 1874. The different types of chiral molecule that have been identified since the first concept of the asymmetric carbon atom are introduced as is the notation used in various disciplines of chemistry to describe the relative or absolute configuration. In the final section, a polemical case for a unified nomenclature is presented.

scholarly journals Twofold C-H Activation-Based Enantio- and Diastereoselective C-H Arylation Using Diarylacetylenes as Rare Arylating Reagents

2021 ◽  
Author(s):  
Panjie Hu ◽  
Lingheng Kong ◽  
Fen Wang ◽  
Xiaolin Zhu ◽  
Xingwei Li
Keyword(s):  
Bond Activation ◽  
Major Product ◽  
Activation Reaction ◽  
Axial Chirality ◽  
Mild Conditions ◽  
Straightforward Method ◽  
Axially Chiral

<p>C-H bond activation has been established as an attractive strategy to access axially chiral biaryls, and the most straightforward method is direct C-H arylation of arenes. However, the arylating source has been limited to several classes of reactive and bulky reagents. Reported herein is rhodium-catalyzed 1:2 coupling of diarylphosphinic amides and diarylacetylenes for enantio- and diastereoselective construction of biaryls with both central and axial chirality. This twofold C-H activation reaction stays contrast to the previously explored Miura-Satoh type 1:2 coupling of arenes and alkynes in terms of chemoselectivity and proceeded under mild conditions with the alkyne acting as a rare arylating reagent. Both C-H activation events are stereo-determining and are under catalyst control, with the 2<sup>nd</sup> C-H activation being diastereo-determining in a remote fashion. Analysis of the stereochemistries of the major and side products suggests moderated enantioselectivity of the initial C-H activation-desymmetrization process. However, the minor stereoisomeric (<i>R</i>) intermediate is consumed more readily in undesired protonolysis, eventually resulting in high enantio- and diastereoselectivity of the major product.</p>

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