scholarly journals Electric field–catalyzed single-molecule Diels-Alder reaction dynamics

2021 ◽  
Vol 7 (4) ◽  
pp. eabf0689
Author(s):  
Chen Yang ◽  
Zitong Liu ◽  
Yanwei Li ◽  
Shuyao Zhou ◽  
Chenxi Lu ◽  
...  
Keyword(s):  
Electric Field ◽  
Single Molecule ◽  
Field Experiments ◽  
Alder Reaction ◽  
Diels Alder ◽  
Charge Transfer Complexes ◽  
Label Free ◽  
Diels Alder Reaction ◽  
Zwitterionic Intermediate

Precise time trajectories and detailed reaction pathways of the Diels-Alder reaction were directly observed using accurate single-molecule detection on an in situ label-free single-molecule electrical detection platform. This study demonstrates the well-accepted concerted mechanism and clarifies the role of charge transfer complexes with endo or exo configurations on the reaction path. An unprecedented stepwise pathway was verified at high temperatures in a high-voltage electric field. Experiments and theoretical results revealed an electric field–catalyzed mechanism that shows the presence of a zwitterionic intermediate with one bond formation and variation of concerted and stepwise reactions by the strength of the electric field, thus establishing a previously unidentified approach for mechanistic control by electric field catalysis.

ChemInform Abstract: Switched Role of Fullerene in the Diels-Alder Reaction: Facile Addition of Dienophiles to the Conjugated Fullerene Diene Moiety.

ChemInform ◽  
2009 ◽  
Vol 40 (24) ◽  
Author(s):  
Jiayao Yao ◽  
Zuo Xiao ◽  
Jianxin Zhang ◽  
Xiaobing Yang ◽  
Liangbing Gan ◽  
...  
Keyword(s):  
Alder Reaction ◽  
Diels Alder ◽  
Diels Alder Reaction

ChemInform Abstract: Highly Diastereoselective Diels-Alder Reaction Mediated by a Chiral Auxiliary Derived from Amino Indanol: The Role of Conformation on Diastereoselectivity.

ChemInform ◽  
2010 ◽  
Vol 27 (5) ◽  
pp. no-no
Author(s):  
I. W. DAVIES ◽  
C. H. SENANAYAKE ◽  
L. CASTONGUAY ◽  
R. D. LARSEN ◽  
T. R. VERHOEVEN ◽  
...  
Keyword(s):  
Alder Reaction ◽  
Diels Alder ◽  
Chiral Auxiliary ◽  
Diels Alder Reaction

scholarly journals On the Role of Hydrogen Bond Strength and Charge Transfer of a Diels-Alder Reaction On-Water: Semiempirical and Free Energy Calculations.

2021 ◽  
Author(s):  
Andrés Henao Aristizàbal ◽  
Yomna Gohar ◽  
René Whilhelm ◽  
Thomas D. Kühne
Keyword(s):  
Hydrogen Bond ◽  
Free Energy ◽  
Charge Transfer ◽  
Hydrogen Bonds ◽  
Density Functional ◽  
Alder Reaction ◽  
Free Energy Calculations ◽  
Diels Alder ◽  
Diels Alder Reaction

Accelerated chemistry at the interface with water has received increasing attention. The mechanisms behind the enhanced reactivity On-Water are not yet clear. In this work we use a Langevin scheme in the spirit of second generation Car-Parrinello to accelerate the second-order density functional Tight-Binding (DFTB2) method in order to investigate the free energy of two Diels-Alder reaction On-Water: the cycloaddition between cyclopentadiene and ethyl cinnamate or thionocinnamate. The only difference between the reactants is the substitution of a carbonyl oxygen for a thiocarbonyl sulfur, making possible the distinction between them as strong and weak hydrogen-bond acceptors. We find a different mechanism for the reaction during the transition states and uncover the role of hydrogen bonds along with the reaction path. Our results suggest that acceleration of Diels-Alder reactions do not arise from an increased number of hydrogen bonds at the transition state and charge transfer plays a significant role. However, the presence of water and hydrogen-bonds is determinant for the catalysis of these reactions.

scholarly journals Heterogeneous Intramolecular Electric Field as a Descriptor of Diels-Alder Reactivity

2020 ◽  
Author(s):  
Matthew Hennefarth ◽  
Anastassia N. Alexandrova
Keyword(s):  
Electric Field ◽  
Electron Density ◽  
Electric Fields ◽  
Alder Reaction ◽  
Diels Alder ◽  
Charge Movement ◽  
External Electric Fields ◽  
Topological Features ◽  
Diels Alder Reaction ◽  
Kinetics Of

<div> <div> <div> <p>External electric fields have proven to be an effective tool in catalysis, on par with pressure and temperature, affecting the thermodynamics and kinetics of a reaction. However, fields in molecules are complicated heterogeneous vector objects, and there is no universal recipe for grasping the exact features of these fields that implicate reactivity. Herein, we demonstrate that topological features of the heterogeneous electric field within the reactant state, as well as of the quantum mechanical electron density – a scalar reporter on the field experienced by the system – can be identified as rigorous descriptors of the reactivity to follow. We scrutinize specifically the Diels-Alder reaction. Its 3-D nature and the lack of a singular directionality of charge movement upon barrier crossing makes the effect of the electric field not obvious. We show that the electric field topology around the dienophile double bond, and the associated changes in the topology of the electron density in this bond are predictors of the reaction barrier. They are also the metrics by which to rationalize and predict how the external field would inhibit or enhance the reaction. The findings pave the way toward designing external fields for catalysis, as well as reading the reactivity without an explicit mechanistic interrogation, for a variety of reactions. </p> </div> </div> </div>

Highly diastereoselective diels-alder reaction mediated by a chiral auxiliary derived from amino indanol: The role of conformation on diastereoselectivity

1995 ◽  
Vol 36 (42) ◽  
pp. 7619-7622 ◽  
Author(s):  
Ian W. Davies ◽  
Chris H. Senanayake ◽  
Laurie Castonguay ◽  
Robert D. Larsen ◽  
Thomas R. Verhoeven ◽  
...  
Keyword(s):  
Alder Reaction ◽  
Diels Alder ◽  
Chiral Auxiliary ◽  
Diels Alder Reaction
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